Travis build: 910

This commit is contained in:
Rohit Tanwar
2018-02-22 15:54:31 +00:00
parent 8e86b83e9a
commit 601344b68a
5 changed files with 480 additions and 434 deletions

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@ -1,44 +1,44 @@
#!/bin/bash
setup_git() {
git config --global user.email "mst10041967@gmail.com"
git config --global user.name "Rohit Tanwar"
}
commit_website_files() {
if [ $TRAVIS_EVENT_TYPE != "pull_request" ]; then
if [ $TRAVIS_BRANCH == "master" ]; then
git checkout master
echo "Committing to master branch..."
git add -A
echo "All files added"
git status
if [ $TRAVIS_EVENT_TYPE == "cron" ]; then
git commit --message "Travis build: $TRAVIS_BUILD_NUMBER [cron]"
elif [ $TRAVIS_EVENT_TYPE == "api" ]; then
git commit --message "Travis build: $TRAVIS_BUILD_NUMBER [custom]"
else
git commit --message "Travis build: $TRAVIS_BUILD_NUMBER"
fi
echo "Files commited"
git status
fi
fi
}
upload_files() {
if [ $TRAVIS_EVENT_TYPE != "pull_request" ]; then
if [ $TRAVIS_BRANCH == "master" ]; then
echo "Pushing to master branch..."
git push --force "https://${GH_TOKEN}@github.com/kriadmin/30-seconds-of-python-code.git" master > /dev/null 2>&1
echo "Pushing done"
echo "Pushing to website"
git subtree push --prefix website "https://${GH_TOKEN}@github.com/kriadmin/30-seconds-of-python-code.git" website
echo "Pushed to master branch"
git status
fi
fi
}
setup_git
commit_website_files
upload_files
#!/bin/bash
setup_git() {
git config --global user.email "mst10041967@gmail.com"
git config --global user.name "Rohit Tanwar"
}
commit_website_files() {
if [ $TRAVIS_EVENT_TYPE != "pull_request" ]; then
if [ $TRAVIS_BRANCH == "master" ]; then
git checkout master
echo "Committing to master branch..."
git add -A
echo "All files added"
git status
if [ $TRAVIS_EVENT_TYPE == "cron" ]; then
git commit --message "Travis build: $TRAVIS_BUILD_NUMBER [cron]"
elif [ $TRAVIS_EVENT_TYPE == "api" ]; then
git commit --message "Travis build: $TRAVIS_BUILD_NUMBER [custom]"
else
git commit --message "Travis build: $TRAVIS_BUILD_NUMBER"
fi
echo "Files commited"
git status
fi
fi
}
upload_files() {
if [ $TRAVIS_EVENT_TYPE != "pull_request" ]; then
if [ $TRAVIS_BRANCH == "master" ]; then
echo "Pushing to master branch..."
git push --force "https://${GH_TOKEN}@github.com/kriadmin/30-seconds-of-python-code.git" master > /dev/null 2>&1
echo "Pushing done"
echo "Pushing to website"
git subtree push --prefix website "https://${GH_TOKEN}@github.com/kriadmin/30-seconds-of-python-code.git" website
echo "Pushed to master branch"
git status
fi
fi
}
setup_git
commit_website_files
upload_files

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@ -1,6 +1,6 @@
![Logo](/icon.png)
# 30-seconds-of-python-code
# 30-seconds-of-python-code [![Tweet](http://jpillora.com/github-twitter-button/img/tweet.png)](http://www.twitter.com/share?text=%2330secondsofcode+30-seconds-of-python-code+-+Python+Implementation+of+30+seconds+of+code%0Ahttps://github.com/kriadmin/30-seconds-of-python-code&url=a")
[![License](https://img.shields.io/aur/license/yaourt.svg)](https://github.com/kriadmin/30-seconds-of-python-code/blob/master/LICENSE) [![Gitter chat](https://img.shields.io/badge/chat-on%20gitter-4FB999.svg)](https://gitter.im/30-seconds-of-python-code/Lobby) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](http://makeapullrequest.com) [![Travis Build](https://travis-ci.org/kriadmin/30-seconds-of-python-code.svg?branch=master)](https://travis-ci.org/kriadmin/30-seconds-of-python-code) [![Insight.io](https://img.shields.io/badge/insight.io-Ready-brightgreen.svg)](https://insight.io/github.com/kriadmin/30-seconds-of-python-code/tree/master/?source=0) [![js-semistandard-style](https://img.shields.io/badge/code%20style-semistandard-brightgreen.svg)](https://github.com/Flet/semistandard)
[![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Fkriadmin%2F30-seconds-of-python-code.svg?type=shield)](https://app.fossa.io/projects/git%2Bgithub.com%2Fkriadmin%2F30-seconds-of-python-code?ref=badge_shield)
@ -52,6 +52,7 @@
### chunk
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Chunks an array into smaller lists of a specified size.
@ -77,6 +78,7 @@ chunk([1,2,3,4,5],2) # [[1,2],[3,4],5]
### compact
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Removes falsey values from a list.
@ -97,6 +99,7 @@ compact([0, 1, False, 2, '', 3, 'a', 's', 34]) # [ 1, 2, 3, 'a', 's', 34 ]
### count_by
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
:information_source: Already implemented via `collections.Counter`
@ -108,7 +111,7 @@ Use `map()` to map the values of the list using the given function. Iterate over
def count_by(arr, fn=lambda x: x):
key = {}
for el in map(fn, arr):
key[el] = 0 if not el in key else key[el]
key[el] = 0 if el not in key else key[el]
key[el] += 1
return key
```
@ -125,6 +128,7 @@ count_by(['one', 'two', 'three'], len) # {3: 2, 5: 1}
### count_occurences
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
:information_source: Already implemented via `list.count()`.
@ -152,6 +156,7 @@ count_occurrences([1, 1, 2, 1, 2, 3], 1) # 3
### deep_flatten
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin), [Meet Zaveri](https://www.github.com/meetzaveri)
Deep flattens a list.
@ -185,6 +190,7 @@ deep_flatten([1, [2], [[3], 4], 5]) # [1,2,3,4,5]
### difference
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Returns the difference between two arrays.
@ -206,6 +212,7 @@ difference([1, 2, 3], [1, 2, 4]) # [3]
### difference_by
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Returns the difference between two list, after applying the provided function to each list element of both.
@ -229,6 +236,7 @@ difference_by([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], lambda v : v['x']) # [ { x
### insertion_sort
<span style="color:grey">Author:-</span> [Meet Zaveri](https://www.github.com/meetzaveri)
<span style="color:grey">Contributors:-</span>[Meet Zaveri](https://www.github.com/meetzaveri), [Rohit Tanwar](https://www.github.com/kriadmin)
On a very basic level, an insertion sort algorithm contains the logic of shifting around and inserting elements in order to sort an unordered list of any size. The way that it goes about inserting elements, however, is what makes insertion sort so very interesting!
@ -256,6 +264,7 @@ print('Sorted %s' %arr) # sorted [2, 3, 4, 6, 7, 9]
### shuffle
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
:information_source: The same algorithm is already implemented via `random.shuffle`.
@ -289,6 +298,7 @@ shuffle(foo) # [2,3,1] , foo = [1,2,3]
### spread
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Implements javascript's `[].concat(...arr)`. Flattens the list(non-deep) and returns an list.
@ -313,6 +323,7 @@ spread([1,2,3,[4,5,6],[7],8,9]) # [1,2,3,4,5,6,7,8,9]
### zip
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
:information_source: Already implemented via `itertools.zip_longest()`
@ -345,13 +356,14 @@ zip(['a'], [1, 2], [True, False], fill_value = '_') # [['a', 1, True], ['_', 2,
### average
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin), [Hui Binyuan](https://www.github.com/huybery)
:information_source: Already implemented via `statistics.mean`. `statistics.mean` takes an array as an argument whereas this function takes variadic arguments.
Returns the average of two or more numbers.
Takes the sum of all the `args` and divides it by `len(args)`. The secind argument `0.0` in sum is to handle floating point division in `python2`.
Takes the sum of all the `args` and divides it by `len(args)`. The second argument `0.0` in sum is to handle floating point division in `python2`.
```py
def average(*args):
return sum(args, 0.0) / len(args)
@ -368,6 +380,7 @@ average(1, 2, 3) # 2.0
### factorial
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Calculates the factorial of a number.
@ -391,6 +404,7 @@ factorial(6) # 720
### gcd
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin), [cclauss][@cclauss]
:information_source: `math.gcd` works with only two numbers
@ -434,6 +448,7 @@ gcd(8,36) # 4
### lcm
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Returns the least common multiple of two or more numbers.
@ -479,6 +494,7 @@ lcm([1, 3, 4], 5) # 60
### max_n
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Returns the `n` maximum elements from the provided list. If `n` is greater than or equal to the provided list's length, then return the original list(sorted in descending order).
@ -506,6 +522,7 @@ max_n([1, 2, 3], 2) # [3,2]
### min_n
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Returns the `n` minimum elements from the provided list. If `n` is greater than or equal to the provided list's length, then return the original list(sorted in ascending order).
@ -534,6 +551,7 @@ min_n([1, 2, 3], 2) # [1,2]
### byte_size
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Returns the length of a string in bytes.
@ -555,6 +573,7 @@ byte_size('Hello World') # 11
### capitalize
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Capitalizes the first letter of a string.
@ -576,6 +595,7 @@ capitalize('fooBar', True) # 'Foobar'
### capitalize_every_word
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Capitalizes the first letter of every word in a string.
@ -596,6 +616,7 @@ capitalize_every_word('hello world!') # 'Hello World!'
### count_vowels
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Retuns `number` of vowels in provided `string`.
@ -620,6 +641,7 @@ count_vowels('gym') # 0
### decapitalize
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Decapitalizes the first letter of a string.
@ -641,6 +663,7 @@ decapitalize('FooBar', True) # 'fOOBAR'
### is_lower_case
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Checks if a string is lower case.
@ -663,6 +686,7 @@ is_lower_case('Ab4') # False
### is_upper_case
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Checks if a string is upper case.
@ -685,6 +709,7 @@ is_upper_case('aB4') # False
### palindrome
<span style="color:grey">Author:-</span> [Rohit Tanwar](https://www.github.com/kriadmin)
<span style="color:grey">Contributors:-</span>[Rohit Tanwar](https://www.github.com/kriadmin)
Returns `True` if the given string is a palindrome, `False` otherwise.

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@ -1,6 +1,6 @@
def count_by(arr, fn=lambda x: x):
key = {}
for el in map(fn, arr):
key[el] = 0 if not el in key else key[el]
key[el] = 0 if el not in key else key[el]
key[el] += 1
return key

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@ -1,8 +1,8 @@
count_vowels
byte_size
capitalize
capitalize_every_word
decapitalize
palindrome
is_upper_case
count_vowels
byte_size
capitalize
capitalize_every_word
decapitalize
palindrome
is_upper_case
is_lower_case

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@ -1,379 +1,400 @@
{% extends "base.html" %}
{% block content %}<div class="row" style="height:calc(100vh - 5.875rem);overflow:hidden"><input id="doc-drawer-checkbox" class="drawer" value="on" type="checkbox"><nav class="col-md-4 col-lg-3" style="border-top:0"><div class="group"><input class="search" id="searchInput" onkeyup="search(this)" type="text"><label id="search-label">Search for snippet...</label></div><label for="doc-drawer-checkbox" class="button drawer-close"></label><h3 style = "">Math</h3><a class="sublink-1" tags="math" href="#average" style="">average</a><a class="sublink-1" tags="math" href="#factorial" style="">factorial</a><a class="sublink-1" tags="math" href="#gcd" style="">gcd</a><a class="sublink-1" tags="math" href="#lcm" style="">lcm</a><a class="sublink-1" tags="math" href="#max_n" style="">max_n</a><a class="sublink-1" tags="math" href="#min_n" style="">min_n</a><h3 style = "">List</h3><a class="sublink-1" tags="list" href="#chunk" style="">chunk</a><a class="sublink-1" tags="list" href="#compact" style="">compact</a><a class="sublink-1" tags="list" href="#count_occurences" style="">count_occurences</a><a class="sublink-1" tags="list" href="#deep_flatten" style="">deep_flatten</a><a class="sublink-1" tags="list" href="#difference" style="">difference</a><a class="sublink-1" tags="list" href="#shuffle" style="">shuffle</a><a class="sublink-1" tags="list" href="#spread" style="">spread</a><a class="sublink-1" tags="list" href="#zip" style="">zip</a><a class="sublink-1" tags="list" href="#count_by" style="">count_by</a><a class="sublink-1" tags="list" href="#difference_by" style="">difference_by</a><h3 style = "">String</h3><a class="sublink-1" tags="string" href="#count_vowels" style="">count_vowels</a><a class="sublink-1" tags="string" href="#byte_size" style="">byte_size</a><a class="sublink-1" tags="string" href="#capitalize" style="">capitalize</a><a class="sublink-1" tags="string" href="#capitalize_every_word" style="">capitalize_every_word</a><a class="sublink-1" tags="string" href="#decapitalize" style="">decapitalize</a><a class="sublink-1" tags="string" href="#palindrome" style="">palindrome</a><a class="sublink-1" tags="string" href="#is_upper_case" style="">is_upper_case</a><a class="sublink-1" tags="string" href="#is_lower_case" style="">is_lower_case</a></nav><main class="col-sm-12 col-md-8 col-lg-9" style="height:100%;overflow-y:auto;background:#eceef2;padding:0"><a id="top"></a><h2 style="text-align:center">Math</h2><div class="card fluid"><h3 id="average" class="section double-padded">average</h3><!--<form action="" method="post"><button type="submit" value="average" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> Already implemented via <code>statistics.mean</code>. <code>statistics.mean</code> takes an array as an argument whereas this function takes variadic arguments.</p>
<p>Returns the average of two or more numbers.</p>
<p>Takes the sum of all the <code>args</code> and divides it by <code>len(args)</code>. The secind argument <code>0.0</code> in sum is to handle floating point division in <code>python2</code>.</p>
<pre class="language-python">def average(*args):
return sum(args, 0.0) / len(args)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">average(*[1, 2, 3]) # 2.0
average(1, 2, 3) # 2.0</pre>
<button class="primary clipboard-copy">📋&nbsp;Copy to clipboard</button></div>
</div><div class="card fluid"><h3 id="factorial" class="section double-padded">factorial</h3><!--<form action="" method="post"><button type="submit" value="factorial" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Calculates the factorial of a number.</p>
<p>Use recursion. If <code>num</code> is less than or equal to <code>1</code>, return <code>1</code>. Otherwise, return the product of <code>num</code> and the factorial of <code>num - 1</code>. Throws an exception if <code>num</code> is a negative or a floating point number.</p>
<pre class="language-python">def factorial(num):
if not ((num &gt;= 0) &amp; (num % 1 == 0)):
raise Exception(
f"Number( {num} ) can't be floating point or negative ")
return 1 if num == 0 else num * factorial(num - 1)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">factorial(6) # 720</pre>
<button class="primary clipboard-copy">📋&nbsp;Copy to clipboard</button></div>
</div><div class="card fluid"><h3 id="gcd" class="section double-padded">gcd</h3><!--<form action="" method="post"><button type="submit" value="gcd" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> <code>math.gcd</code> works with only two numbers</p>
<p>Calculates the greatest common divisor between two or more numbers/lists.</p>
<p>The <code>helperGcdfunction</code> uses recursion. Base case is when <code>y</code> equals <code>0</code>. In this case, return <code>x</code>. Otherwise, return the GCD of <code>y</code> and the remainder of the division <code>x/y</code>.</p>
<p>Uses the reduce function from the inbuilt module <code>functools</code>. Also defines a method <code>spread</code> for javascript like spreading of lists.</p>
<pre class="language-python">from functools import reduce
def spread(arg):
ret = []
for i in arg:
if isinstance(i, list):
ret.extend(i)
else:
ret.append(i)
return ret
def gcd(*args):
numbers = []
numbers.extend(spread(list(args)))
def _gcd(x, y):
return x if not y else gcd(y, x % y)
return reduce((lambda x, y: _gcd(x, y)), numbers)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">gcd(8,36) # 4</pre>
<button class="primary clipboard-copy">📋&nbsp;Copy to clipboard</button></div>
</div><div class="card fluid"><h3 id="lcm" class="section double-padded">lcm</h3><!--<form action="" method="post"><button type="submit" value="lcm" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the least common multiple of two or more numbers.</p>
<p>Use the <code>greatest common divisor (GCD)</code> formula and the fact that <code>lcm(x,y) = x * y / gcd(x,y)</code> to determine the least common multiple. The GCD formula uses recursion.</p>
<p>Uses <code>reduce</code> function from the inbuilt module <code>functools</code>. Also defines a method <code>spread</code> for javascript like spreading of lists.</p>
<pre class="language-python">from functools import reduce
def spread(arg):
ret = []
for i in arg:
if isinstance(i, list):
ret.extend(i)
else:
ret.append(i)
return ret
def lcm(*args):
numbers = []
numbers.extend(spread(list(args)))
def _gcd(x, y):
return x if not y else gcd(y, x % y)
def _lcm(x, y):
return x * y / _gcd(x, y)
return reduce((lambda x, y: _lcm(x, y)), numbers)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">lcm(12, 7) # 84
lcm([1, 3, 4], 5) # 60</pre>
<button class="primary clipboard-copy">📋&nbsp;Copy to clipboard</button></div>
</div><div class="card fluid"><h3 id="max_n" class="section double-padded">max_n</h3><!--<form action="" method="post"><button type="submit" value="max_n" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the <code>n</code> maximum elements from the provided list. If <code>n</code> is greater than or equal to the provided list's length, then return the original list(sorted in descending order).</p>
<p>Use <code>list.sort()</code> combined with the <code>deepcopy</code> function from the inbuilt <code>copy</code> module to create a shallow clone of the list and sort it in ascending order and then use <code>list.reverse()</code> reverse it to make it descending order. Use <code>[:n]</code> to get the specified number of elements. Omit the second argument, <code>n</code>, to get a one-element array</p>
<pre class="language-python">from copy import deepcopy
def max_n(arr, n=1):
numbers = deepcopy(arr)
numbers.sort()
numbers.reverse()
return numbers[:n]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">max_n([1, 2, 3]) # [3]
max_n([1, 2, 3], 2) # [3,2]</pre>
<button class="primary clipboard-copy">📋&nbsp;Copy to clipboard</button></div>
</div><div class="card fluid"><h3 id="min_n" class="section double-padded">min_n</h3><!--<form action="" method="post"><button type="submit" value="min_n" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the <code>n</code> minimum elements from the provided list. If <code>n</code> is greater than or equal to the provided list's length, then return the original list(sorted in ascending order).</p>
<p>Use <code>list.sort()</code> combined with the <code>deepcopy</code> function from the inbuilt <code>copy</code> module to create a shallow clone of the list and sort it in ascending order. Use <code>[:n]</code> to get the specified number of elements. Omit the second argument, <code>n</code>, to get a one-element array</p>
<pre class="language-python">from copy import deepcopy
def min_n(arr, n=1):
numbers = deepcopy(arr)
numbers.sort()
return numbers[:n]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">min_n([1, 2, 3]) # [1]
min_n([1, 2, 3], 2) # [1,2]</pre>
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</div><h2 style="text-align:center">List</h2><div class="card fluid"><h3 id="chunk" class="section double-padded">chunk</h3><!--<form action="" method="post"><button type="submit" value="chunk" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Chunks an array into smaller lists of a specified size.</p>
<p>Uses <code>range</code> to create a list of desired size. Then use <code>map</code> on this list and fill it with splices of <code>arr</code>.</p>
<pre class="language-python">from math import ceil
def chunk(arr, size):
return list(
map(lambda x: arr[x * size:x * size + size],
list(range(0, ceil(len(arr) / size)))))</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">chunk([1,2,3,4,5],2) # [[1,2],[3,4],5]</pre>
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</div><div class="card fluid"><h3 id="compact" class="section double-padded">compact</h3><!--<form action="" method="post"><button type="submit" value="compact" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Removes falsey values from a list.</p>
<p>Use <code>filter()</code> to filter out falsey values (False, None, 0, and "").</p>
<pre class="language-python">def compact(arr):
return list(filter(lambda x: bool(x), arr))</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">compact([0, 1, False, 2, '', 3, 'a', 's', 34]) # [ 1, 2, 3, 'a', 's', 34 ]</pre>
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</div><div class="card fluid"><h3 id="count_occurences" class="section double-padded">count_occurences</h3><!--<form action="" method="post"><button type="submit" value="count_occurences" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> Already implemented via <code>list.count()</code>.</p>
<p>Counts the occurrences of a value in an list.</p>
<p>Uses the <code>reduce</code> functin from built-in module <code>functools</code> to increment a counter each time you encounter the specific value inside the list.</p>
<pre class="language-python">def count_occurences(arr, val):
return reduce(
(lambda x, y: x + 1 if y == val and type(y) == type(val) else x + 0),
arr)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">count_occurrences([1, 1, 2, 1, 2, 3], 1) # 3</pre>
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</div><div class="card fluid"><h3 id="deep_flatten" class="section double-padded">deep_flatten</h3><!--<form action="" method="post"><button type="submit" value="deep_flatten" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Deep flattens a list.</p>
<p>Use recursion. Use <code>list.extend()</code> with an empty array (<code>result</code>) and the spread function to flatten a list. Recursively flatten each element that is a list.</p>
<pre class="language-python">def spread(arg):
ret = []
for i in arg:
if isinstance(i, list):
ret.extend(i)
else:
ret.append(i)
return ret
def deep_flatten(arr):
result = []
result.extend(
spread(list(map(lambda x: deep(x) if type(x) == list else x, arr))))
return result</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">deep_flatten([1, [2], [[3], 4], 5]) # [1,2,3,4,5]</pre>
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</div><div class="card fluid"><h3 id="difference" class="section double-padded">difference</h3><!--<form action="" method="post"><button type="submit" value="difference" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the difference between two arrays.</p>
<p>Create a <code>set</code> from <code>b</code>, then use list comprehension to only keep values not contained in <code>b</code></p>
<pre class="language-python">def difference(a, b):
b = set(b)
return [item for item in a if item not in b]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">difference([1, 2, 3], [1, 2, 4]) # [3]</pre>
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</div><div class="card fluid"><h3 id="shuffle" class="section double-padded">shuffle</h3><!--<form action="" method="post"><button type="submit" value="shuffle" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> The same algorithm is already implemented via <code>random.shuffle</code>.</p>
<p>Randomizes the order of the values of an list, returning a new list.</p>
<p>Uses the <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates algorithm</a> to reorder the elements of the list.</p>
<pre class="language-python">from copy import deepcopy
from random import randint
def shuffle(arr):
temp_arr = deepcopy(arr)
m = len(temp_arr)
while (m):
m -= 1
i = randint(0, m)
temp_arr[m], temp_arr[i] = temp_arr[i], temp_arr[m]
return temp_arr</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">foo = [1,2,3]
shuffle(foo) # [2,3,1] , foo = [1,2,3]</pre>
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</div><div class="card fluid"><h3 id="spread" class="section double-padded">spread</h3><!--<form action="" method="post"><button type="submit" value="spread" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Implements javascript's <code>[].concat(...arr)</code>. Flattens the list(non-deep) and returns an list.</p>
<pre class="language-python">def spread(arg):
ret = []
for i in arg:
if isinstance(i, list):
ret.extend(i)
else:
ret.append(i)
return ret</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">spread([1,2,3,[4,5,6],[7],8,9]) # [1,2,3,4,5,6,7,8,9]</pre>
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</div><div class="card fluid"><h3 id="zip" class="section double-padded">zip</h3><!--<form action="" method="post"><button type="submit" value="zip" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> Already implemented via <code>itertools.zip_longest()</code></p>
<p>Creates a list of elements, grouped based on the position in the original lists.</p>
<p>Use <code>max</code> combined with <code>list comprehension</code> to get the length of the longest list in the arguments. Loops for <code>max_length</code> times grouping elements. If lengths of <code>lists</code> vary <code>fill_value</code> is used. By default <code>fill_value</code> is <code>None</code>.</p>
<pre class="language-python">def zip(*args, fillvalue=None):
max_length = max([len(arr) for arr in args])
result = []
for i in range(max_length):
result.append([
args[k][i] if i &lt; len(args[k]) else None for k in range(len(args))
])
return result</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">zip(['a', 'b'], [1, 2], [True, False]) # [['a', 1, True], ['b', 2, False]]
zip(['a'], [1, 2], [True, False]) # [['a', 1, True], [None, 2, False]]
zip(['a'], [1, 2], [True, False], fill_value = '_') # [['a', 1, True], ['_', 2, False]]</pre>
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</div><div class="card fluid"><h3 id="count_by" class="section double-padded">count_by</h3><!--<form action="" method="post"><button type="submit" value="count_by" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> Already implemented via <code>collections.Counter</code></p>
<p>Groups the elements of a list based on the given function and returns the count of elements in each group.</p>
<p>Use <code>map()</code> to map the values of the list using the given function. Iterate over the map and increase the the elements count each time it occurs.</p>
<pre class="language-python">def count_by(arr, fn=lambda x: x):
key = {}
for el in map(fn, arr):
key[el] = 0 if not el in key else key[el]
key[el] += 1
return key</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">from math import floor
count_by([6.1, 4.2, 6.3], floor) # {4: 1, 6: 2}
count_by(['one', 'two', 'three'], len) # {3: 2, 5: 1}</pre>
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</div><div class="card fluid"><h3 id="difference_by" class="section double-padded">difference_by</h3><!--<form action="" method="post"><button type="submit" value="difference_by" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the difference between two list, after applying the provided function to each list element of both.</p>
<p>Create a <code>set</code> by applying <code>fn</code> to each element in <code>b</code>, then use list comprehension in combination with fn on a to only keep values not contained in the previously created <code>set</code>.</p>
<pre class="language-python">def difference_by(a, b, fn):
b = set(map(fn, b))
return [item for item in a if fn(item) not in b]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">from math import floor
difference_by([2.1, 1.2], [2.3, 3.4],floor) # [1.2]
difference_by([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], lambda v : v['x']) # [ { x: 2 } ]</pre>
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</div><h2 style="text-align:center">String</h2><div class="card fluid"><h3 id="count_vowels" class="section double-padded">count_vowels</h3><!--<form action="" method="post"><button type="submit" value="count_vowels" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Retuns <code>number</code> of vowels in provided <code>string</code>.</p>
<p>Use a regular expression to count the number of vowels <code>(A, E, I, O, U)</code> in a string.</p>
<pre class="language-python">import re
def count_vowels(str):
return len(len(re.findall(r'[aeiou]', str, re.IGNORECASE)))</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">count_vowels('foobar') # 3
count_vowels('gym') # 0</pre>
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</div><div class="card fluid"><h3 id="byte_size" class="section double-padded">byte_size</h3><!--<form action="" method="post"><button type="submit" value="byte_size" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the length of a string in bytes.</p>
<p><code>utf-8</code> encodes a given string and find its length.</p>
<pre class="language-python">def byte_size(string):
return(len(string.encode('utf-8')))</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">byte_size('😀') # 4
byte_size('Hello World') # 11</pre>
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</div><div class="card fluid"><h3 id="capitalize" class="section double-padded">capitalize</h3><!--<form action="" method="post"><button type="submit" value="capitalize" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Capitalizes the first letter of a string.</p>
<p>Capitalizes the fist letter of the sring and then adds it with rest of the string. Omit the <code>lower_rest</code> parameter to keep the rest of the string intact, or set it to <code>true</code> to convert to lowercase.</p>
<pre class="language-python">def capitalize(string, lower_rest=False):
return string[:1].upper() + (string[1:].lower() if lower_rest else string[1:])</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">capitalize('fooBar') # 'FooBar'
capitalize('fooBar', True) # 'Foobar'</pre>
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</div><div class="card fluid"><h3 id="capitalize_every_word" class="section double-padded">capitalize_every_word</h3><!--<form action="" method="post"><button type="submit" value="capitalize_every_word" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Capitalizes the first letter of every word in a string.</p>
<p>Uses <code>str.title</code> to capitalize first letter of evry word in the string.</p>
<pre class="language-python">def capitalize_every_word(string):
return string.title()</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">capitalize_every_word('hello world!') # 'Hello World!'</pre>
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</div><div class="card fluid"><h3 id="decapitalize" class="section double-padded">decapitalize</h3><!--<form action="" method="post"><button type="submit" value="decapitalize" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Decapitalizes the first letter of a string.</p>
<p>Decapitalizes the fist letter of the sring and then adds it with rest of the string. Omit the <code>upper_rest</code> parameter to keep the rest of the string intact, or set it to <code>true</code> to convert to uppercase.</p>
<pre class="language-python">def decapitalize(string, upper_rest=False):
return str[:1].lower() + (str[1:].upper() if upper_rest else str[1:])</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">decapitalize('FooBar') # 'fooBar'
decapitalize('FooBar', True) # 'fOOBAR'</pre>
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</div><div class="card fluid"><h3 id="palindrome" class="section double-padded">palindrome</h3><!--<form action="" method="post"><button type="submit" value="palindrome" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns <code>True</code> if the given string is a palindrome, <code>False</code> otherwise.</p>
<p>Convert string <code>str.lower()</code> and use <code>re.sub</code> to remove non-alphanumeric characters from it. Then compare the new string to the reversed.</p>
<pre class="language-python">def palindrome(string):
from re import sub
s = sub('[\W_]', '', string.lower())
return s == s[::-1]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">palindrome('taco cat') # True</pre>
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</div><div class="card fluid"><h3 id="is_upper_case" class="section double-padded">is_upper_case</h3><!--<form action="" method="post"><button type="submit" value="is_upper_case" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Checks if a string is upper case.</p>
<p>Convert the given string to upper case, using <code>str.upper()</code> method and compare it to the original.</p>
<pre class="language-python">def is_upper_case(str):
return str == str.upper()</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">is_upper_case('ABC') # True
is_upper_case('a3@$') # True
is_upper_case('aB4') # False</pre>
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</div><div class="card fluid"><h3 id="is_lower_case" class="section double-padded">is_lower_case</h3><!--<form action="" method="post"><button type="submit" value="is_lower_case" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Checks if a string is lower case.</p>
<p>Convert the given string to lower case, using <code>str.lower()</code> method and compare it to the original.</p>
<pre class="language-python">def is_lower_case(str):
return str == str.lower()</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">is_lower_case('abc') # True
is_lower_case('a3@$') # True
is_lower_case('Ab4') # False</pre>
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<footer><p style="display:inline-block"><strong>30 seconds of python code</strong> is licensed under the <a href="https://github.com/kriadmin/30-seconds-of-python-code/blob/master/LICENSE">GPL-3.0</a> license.<br>Icons made by <a href="https://www.flaticon.com/authors/smashicons">Smashicons</a> from <a href="https://www.flaticon.com/">www.flaticon.com</a> is licensed by <a href="http://creativecommons.org/licenses/by/3.0/">CC 3.0 BY</a>.<br>Ribbon made by <a href="https://github.com/tholman/github-corners">Tim Holman</a> is licensed by <a href="https://opensource.org/licenses/MIT">The MIT License</a><br>Built with the <a href="https://minicss.org">mini.css framework</a>.</p></footer>
{% extends "base.html" %}
{% block content %}<div class="row" style="height:calc(100vh - 5.875rem);overflow:hidden"><input id="doc-drawer-checkbox" class="drawer" value="on" type="checkbox"><nav class="col-md-4 col-lg-3" style="border-top:0"><div class="group"><input class="search" id="searchInput" onkeyup="search(this)" type="text"><label id="search-label">Search for snippet...</label></div><label for="doc-drawer-checkbox" class="button drawer-close"></label><h3 style = "">Math</h3><a class="sublink-1" tags="math" href="#average" style="">average</a><a class="sublink-1" tags="math" href="#factorial" style="">factorial</a><a class="sublink-1" tags="math" href="#gcd" style="">gcd</a><a class="sublink-1" tags="math" href="#lcm" style="">lcm</a><a class="sublink-1" tags="math" href="#max_n" style="">max_n</a><a class="sublink-1" tags="math" href="#min_n" style="">min_n</a><h3 style = "">List</h3><a class="sublink-1" tags="list" href="#chunk" style="">chunk</a><a class="sublink-1" tags="list" href="#compact" style="">compact</a><a class="sublink-1" tags="list" href="#count_occurences" style="">count_occurences</a><a class="sublink-1" tags="list" href="#deep_flatten" style="">deep_flatten</a><a class="sublink-1" tags="list" href="#difference" style="">difference</a><a class="sublink-1" tags="list" href="#shuffle" style="">shuffle</a><a class="sublink-1" tags="list" href="#spread" style="">spread</a><a class="sublink-1" tags="list" href="#zip" style="">zip</a><a class="sublink-1" tags="list" href="#count_by" style="">count_by</a><a class="sublink-1" tags="list" href="#difference_by" style="">difference_by</a><a class="sublink-1" tags="list" href="#insertion_sort" style="">insertion_sort</a><h3 style = "">String</h3><a class="sublink-1" tags="string" href="#count_vowels" style="">count_vowels</a><a class="sublink-1" tags="string" href="#byte_size" style="">byte_size</a><a class="sublink-1" tags="string" href="#capitalize" style="">capitalize</a><a class="sublink-1" tags="string" href="#capitalize_every_word" style="">capitalize_every_word</a><a class="sublink-1" tags="string" href="#decapitalize" style="">decapitalize</a><a class="sublink-1" tags="string" href="#palindrome" style="">palindrome</a><a class="sublink-1" tags="string" href="#is_upper_case" style="">is_upper_case</a><a class="sublink-1" tags="string" href="#is_lower_case" style="">is_lower_case</a></nav><main class="col-sm-12 col-md-8 col-lg-9" style="height:100%;overflow-y:auto;background:#eceef2;padding:0"><a id="top"></a><h2 style="text-align:center">Math</h2><div class="card fluid"><h3 id="average" class="section double-padded">average</h3><!--<form action="" method="post"><button type="submit" value="average" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> Already implemented via <code>statistics.mean</code>. <code>statistics.mean</code> takes an array as an argument whereas this function takes variadic arguments.</p>
<p>Returns the average of two or more numbers.</p>
<p>Takes the sum of all the <code>args</code> and divides it by <code>len(args)</code>. The second argument <code>0.0</code> in sum is to handle floating point division in <code>python2</code>.</p>
<pre class="language-python">def average(*args):
return sum(args, 0.0) / len(args)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">average(*[1, 2, 3]) # 2.0
average(1, 2, 3) # 2.0</pre>
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</div><div class="card fluid"><h3 id="factorial" class="section double-padded">factorial</h3><!--<form action="" method="post"><button type="submit" value="factorial" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Calculates the factorial of a number.</p>
<p>Use recursion. If <code>num</code> is less than or equal to <code>1</code>, return <code>1</code>. Otherwise, return the product of <code>num</code> and the factorial of <code>num - 1</code>. Throws an exception if <code>num</code> is a negative or a floating point number.</p>
<pre class="language-python">def factorial(num):
if not ((num &gt;= 0) &amp; (num % 1 == 0)):
raise Exception(
f"Number( {num} ) can't be floating point or negative ")
return 1 if num == 0 else num * factorial(num - 1)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">factorial(6) # 720</pre>
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</div><div class="card fluid"><h3 id="gcd" class="section double-padded">gcd</h3><!--<form action="" method="post"><button type="submit" value="gcd" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> <code>math.gcd</code> works with only two numbers</p>
<p>Calculates the greatest common divisor between two or more numbers/lists.</p>
<p>The <code>helperGcdfunction</code> uses recursion. Base case is when <code>y</code> equals <code>0</code>. In this case, return <code>x</code>. Otherwise, return the GCD of <code>y</code> and the remainder of the division <code>x/y</code>.</p>
<p>Uses the reduce function from the inbuilt module <code>functools</code>. Also defines a method <code>spread</code> for javascript like spreading of lists.</p>
<pre class="language-python">from functools import reduce
def spread(arg):
ret = []
for i in arg:
if isinstance(i, list):
ret.extend(i)
else:
ret.append(i)
return ret
def gcd(*args):
numbers = []
numbers.extend(spread(list(args)))
def _gcd(x, y):
return x if not y else gcd(y, x % y)
return reduce((lambda x, y: _gcd(x, y)), numbers)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">gcd(8,36) # 4</pre>
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</div><div class="card fluid"><h3 id="lcm" class="section double-padded">lcm</h3><!--<form action="" method="post"><button type="submit" value="lcm" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the least common multiple of two or more numbers.</p>
<p>Use the <code>greatest common divisor (GCD)</code> formula and the fact that <code>lcm(x,y) = x * y / gcd(x,y)</code> to determine the least common multiple. The GCD formula uses recursion.</p>
<p>Uses <code>reduce</code> function from the inbuilt module <code>functools</code>. Also defines a method <code>spread</code> for javascript like spreading of lists.</p>
<pre class="language-python">from functools import reduce
def spread(arg):
ret = []
for i in arg:
if isinstance(i, list):
ret.extend(i)
else:
ret.append(i)
return ret
def lcm(*args):
numbers = []
numbers.extend(spread(list(args)))
def _gcd(x, y):
return x if not y else _gcd(y, x % y)
def _lcm(x, y):
return x * y / _gcd(x, y)
return reduce((lambda x, y: _lcm(x, y)), numbers)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">lcm(12, 7) # 84
lcm([1, 3, 4], 5) # 60</pre>
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</div><div class="card fluid"><h3 id="max_n" class="section double-padded">max_n</h3><!--<form action="" method="post"><button type="submit" value="max_n" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the <code>n</code> maximum elements from the provided list. If <code>n</code> is greater than or equal to the provided list's length, then return the original list(sorted in descending order).</p>
<p>Use <code>list.sort()</code> combined with the <code>deepcopy</code> function from the inbuilt <code>copy</code> module to create a shallow clone of the list and sort it in ascending order and then use <code>list.reverse()</code> reverse it to make it descending order. Use <code>[:n]</code> to get the specified number of elements. Omit the second argument, <code>n</code>, to get a one-element array</p>
<pre class="language-python">from copy import deepcopy
def max_n(arr, n=1):
numbers = deepcopy(arr)
numbers.sort()
numbers.reverse()
return numbers[:n]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">max_n([1, 2, 3]) # [3]
max_n([1, 2, 3], 2) # [3,2]</pre>
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</div><div class="card fluid"><h3 id="min_n" class="section double-padded">min_n</h3><!--<form action="" method="post"><button type="submit" value="min_n" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the <code>n</code> minimum elements from the provided list. If <code>n</code> is greater than or equal to the provided list's length, then return the original list(sorted in ascending order).</p>
<p>Use <code>list.sort()</code> combined with the <code>deepcopy</code> function from the inbuilt <code>copy</code> module to create a shallow clone of the list and sort it in ascending order. Use <code>[:n]</code> to get the specified number of elements. Omit the second argument, <code>n</code>, to get a one-element array</p>
<pre class="language-python">from copy import deepcopy
def min_n(arr, n=1):
numbers = deepcopy(arr)
numbers.sort()
return numbers[:n]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">min_n([1, 2, 3]) # [1]
min_n([1, 2, 3], 2) # [1,2]</pre>
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</div><h2 style="text-align:center">List</h2><div class="card fluid"><h3 id="chunk" class="section double-padded">chunk</h3><!--<form action="" method="post"><button type="submit" value="chunk" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Chunks an array into smaller lists of a specified size.</p>
<p>Uses <code>range</code> to create a list of desired size. Then use <code>map</code> on this list and fill it with splices of <code>arr</code>.</p>
<pre class="language-python">from math import ceil
def chunk(arr, size):
return list(
map(lambda x: arr[x * size:x * size + size],
list(range(0, ceil(len(arr) / size)))))</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">chunk([1,2,3,4,5],2) # [[1,2],[3,4],5]</pre>
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</div><div class="card fluid"><h3 id="compact" class="section double-padded">compact</h3><!--<form action="" method="post"><button type="submit" value="compact" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Removes falsey values from a list.</p>
<p>Use <code>filter()</code> to filter out falsey values (False, None, 0, and "").</p>
<pre class="language-python">def compact(arr):
return list(filter(lambda x: bool(x), arr))</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">compact([0, 1, False, 2, '', 3, 'a', 's', 34]) # [ 1, 2, 3, 'a', 's', 34 ]</pre>
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</div><div class="card fluid"><h3 id="count_occurences" class="section double-padded">count_occurences</h3><!--<form action="" method="post"><button type="submit" value="count_occurences" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> Already implemented via <code>list.count()</code>.</p>
<p>Counts the occurrences of a value in an list.</p>
<p>Uses the <code>reduce</code> functin from built-in module <code>functools</code> to increment a counter each time you encounter the specific value inside the list.</p>
<pre class="language-python">from functools import reduce
def count_occurences(arr, val):
return reduce(
(lambda x, y: x + 1 if y == val and type(y) == type(val) else x + 0),
arr)</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">count_occurrences([1, 1, 2, 1, 2, 3], 1) # 3</pre>
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</div><div class="card fluid"><h3 id="deep_flatten" class="section double-padded">deep_flatten</h3><!--<form action="" method="post"><button type="submit" value="deep_flatten" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Deep flattens a list.</p>
<p>Use recursion. Use <code>list.extend()</code> with an empty array (<code>result</code>) and the spread function to flatten a list. Recursively flatten each element that is a list.</p>
<pre class="language-python">def spread(arg):
ret = []
for i in arg:
if isinstance(i, list):
ret.extend(i)
else:
ret.append(i)
return ret
def deep_flatten(arr):
result = []
result.extend(
spread(list(map(lambda x: deep_flatten(x) if type(x) == list else x, arr))))
return result</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">deep_flatten([1, [2], [[3], 4], 5]) # [1,2,3,4,5]</pre>
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</div><div class="card fluid"><h3 id="difference" class="section double-padded">difference</h3><!--<form action="" method="post"><button type="submit" value="difference" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the difference between two arrays.</p>
<p>Create a <code>set</code> from <code>b</code>, then use list comprehension to only keep values not contained in <code>b</code></p>
<pre class="language-python">def difference(a, b):
b = set(b)
return [item for item in a if item not in b]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">difference([1, 2, 3], [1, 2, 4]) # [3]</pre>
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</div><div class="card fluid"><h3 id="shuffle" class="section double-padded">shuffle</h3><!--<form action="" method="post"><button type="submit" value="shuffle" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> The same algorithm is already implemented via <code>random.shuffle</code>.</p>
<p>Randomizes the order of the values of an list, returning a new list.</p>
<p>Uses the <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates algorithm</a> to reorder the elements of the list.</p>
<pre class="language-python">from copy import deepcopy
from random import randint
def shuffle(arr):
temp_arr = deepcopy(arr)
m = len(temp_arr)
while (m):
m -= 1
i = randint(0, m)
temp_arr[m], temp_arr[i] = temp_arr[i], temp_arr[m]
return temp_arr</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">foo = [1,2,3]
shuffle(foo) # [2,3,1] , foo = [1,2,3]</pre>
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</div><div class="card fluid"><h3 id="spread" class="section double-padded">spread</h3><!--<form action="" method="post"><button type="submit" value="spread" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Implements javascript's <code>[].concat(...arr)</code>. Flattens the list(non-deep) and returns an list.</p>
<pre class="language-python">def spread(arg):
ret = []
for i in arg:
if isinstance(i, list):
ret.extend(i)
else:
ret.append(i)
return ret</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">spread([1,2,3,[4,5,6],[7],8,9]) # [1,2,3,4,5,6,7,8,9]</pre>
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</div><div class="card fluid"><h3 id="zip" class="section double-padded">zip</h3><!--<form action="" method="post"><button type="submit" value="zip" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> Already implemented via <code>itertools.zip_longest()</code></p>
<p>Creates a list of elements, grouped based on the position in the original lists.</p>
<p>Use <code>max</code> combined with <code>list comprehension</code> to get the length of the longest list in the arguments. Loops for <code>max_length</code> times grouping elements. If lengths of <code>lists</code> vary <code>fill_value</code> is used. By default <code>fill_value</code> is <code>None</code>.</p>
<pre class="language-python">def zip(*args, fillvalue=None):
max_length = max([len(arr) for arr in args])
result = []
for i in range(max_length):
result.append([
args[k][i] if i &lt; len(args[k]) else None for k in range(len(args))
])
return result</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">zip(['a', 'b'], [1, 2], [True, False]) # [['a', 1, True], ['b', 2, False]]
zip(['a'], [1, 2], [True, False]) # [['a', 1, True], [None, 2, False]]
zip(['a'], [1, 2], [True, False], fill_value = '_') # [['a', 1, True], ['_', 2, False]]</pre>
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</div><div class="card fluid"><h3 id="count_by" class="section double-padded">count_by</h3><!--<form action="" method="post"><button type="submit" value="count_by" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p><emoji></emoji> Already implemented via <code>collections.Counter</code></p>
<p>Groups the elements of a list based on the given function and returns the count of elements in each group.</p>
<p>Use <code>map()</code> to map the values of the list using the given function. Iterate over the map and increase the the elements count each time it occurs.</p>
<pre class="language-python">def count_by(arr, fn=lambda x: x):
key = {}
for el in map(fn, arr):
key[el] = 0 if el not in key else key[el]
key[el] += 1
return key</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">from math import floor
count_by([6.1, 4.2, 6.3], floor) # {4: 1, 6: 2}
count_by(['one', 'two', 'three'], len) # {3: 2, 5: 1}</pre>
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</div><div class="card fluid"><h3 id="difference_by" class="section double-padded">difference_by</h3><!--<form action="" method="post"><button type="submit" value="difference_by" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the difference between two list, after applying the provided function to each list element of both.</p>
<p>Create a <code>set</code> by applying <code>fn</code> to each element in <code>b</code>, then use list comprehension in combination with fn on a to only keep values not contained in the previously created <code>set</code>.</p>
<pre class="language-python">def difference_by(a, b, fn):
b = set(map(fn, b))
return [item for item in a if fn(item) not in b]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">from math import floor
difference_by([2.1, 1.2], [2.3, 3.4],floor) # [1.2]
difference_by([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], lambda v : v['x']) # [ { x: 2 } ]</pre>
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</div><div class="card fluid"><h3 id="insertion_sort" class="section double-padded">insertion_sort</h3><!--<form action="" method="post"><button type="submit" value="insertion_sort" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>On a very basic level, an insertion sort algorithm contains the logic of shifting around and inserting elements in order to sort an unordered list of any size. The way that it goes about inserting elements, however, is what makes insertion sort so very interesting!</p>
<pre class="language-python">def insertion_sort(arr):
for i in range(1, len(arr)):
key = arr[i]
j = i - 1
while j &gt;= 0 and key &lt; arr[j]:
arr[j + 1] = arr[j]
j -= 1
arr[j + 1] = key</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">arr = [7,4,9,2,6,3]
insertionsort(arr)
print('Sorted %s' %arr) # sorted [2, 3, 4, 6, 7, 9]</pre>
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</div><h2 style="text-align:center">String</h2><div class="card fluid"><h3 id="count_vowels" class="section double-padded">count_vowels</h3><!--<form action="" method="post"><button type="submit" value="count_vowels" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Retuns <code>number</code> of vowels in provided <code>string</code>.</p>
<p>Use a regular expression to count the number of vowels <code>(A, E, I, O, U)</code> in a string.</p>
<pre class="language-python">import re
def count_vowels(str):
return len(len(re.findall(r'[aeiou]', str, re.IGNORECASE)))</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">count_vowels('foobar') # 3
count_vowels('gym') # 0</pre>
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</div><div class="card fluid"><h3 id="byte_size" class="section double-padded">byte_size</h3><!--<form action="" method="post"><button type="submit" value="byte_size" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns the length of a string in bytes.</p>
<p><code>utf-8</code> encodes a given string and find its length.</p>
<pre class="language-python">def byte_size(string):
return(len(string.encode('utf-8')))</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">byte_size('😀') # 4
byte_size('Hello World') # 11</pre>
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</div><div class="card fluid"><h3 id="capitalize" class="section double-padded">capitalize</h3><!--<form action="" method="post"><button type="submit" value="capitalize" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Capitalizes the first letter of a string.</p>
<p>Capitalizes the fist letter of the sring and then adds it with rest of the string. Omit the <code>lower_rest</code> parameter to keep the rest of the string intact, or set it to <code>true</code> to convert to lowercase.</p>
<pre class="language-python">def capitalize(string, lower_rest=False):
return string[:1].upper() + (string[1:].lower() if lower_rest else string[1:])</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">capitalize('fooBar') # 'FooBar'
capitalize('fooBar', True) # 'Foobar'</pre>
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</div><div class="card fluid"><h3 id="capitalize_every_word" class="section double-padded">capitalize_every_word</h3><!--<form action="" method="post"><button type="submit" value="capitalize_every_word" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Capitalizes the first letter of every word in a string.</p>
<p>Uses <code>str.title</code> to capitalize first letter of evry word in the string.</p>
<pre class="language-python">def capitalize_every_word(string):
return string.title()</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">capitalize_every_word('hello world!') # 'Hello World!'</pre>
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</div><div class="card fluid"><h3 id="decapitalize" class="section double-padded">decapitalize</h3><!--<form action="" method="post"><button type="submit" value="decapitalize" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Decapitalizes the first letter of a string.</p>
<p>Decapitalizes the fist letter of the sring and then adds it with rest of the string. Omit the <code>upper_rest</code> parameter to keep the rest of the string intact, or set it to <code>true</code> to convert to uppercase.</p>
<pre class="language-python">def decapitalize(string, upper_rest=False):
return str[:1].lower() + (str[1:].upper() if upper_rest else str[1:])</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">decapitalize('FooBar') # 'fooBar'
decapitalize('FooBar', True) # 'fOOBAR'</pre>
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</div><div class="card fluid"><h3 id="palindrome" class="section double-padded">palindrome</h3><!--<form action="" method="post"><button type="submit" value="palindrome" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Returns <code>True</code> if the given string is a palindrome, <code>False</code> otherwise.</p>
<p>Convert string <code>str.lower()</code> and use <code>re.sub</code> to remove non-alphanumeric characters from it. Then compare the new string to the reversed.</p>
<pre class="language-python">def palindrome(string):
from re import sub
s = sub('[\W_]', '', string.lower())
return s == s[::-1]</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">palindrome('taco cat') # True</pre>
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</div><div class="card fluid"><h3 id="is_upper_case" class="section double-padded">is_upper_case</h3><!--<form action="" method="post"><button type="submit" value="is_upper_case" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Checks if a string is upper case.</p>
<p>Convert the given string to upper case, using <code>str.upper()</code> method and compare it to the original.</p>
<pre class="language-python">def is_upper_case(str):
return str == str.upper()</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">is_upper_case('ABC') # True
is_upper_case('a3@$') # True
is_upper_case('aB4') # False</pre>
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</div><div class="card fluid"><h3 id="is_lower_case" class="section double-padded">is_lower_case</h3><!--<form action="" method="post"><button type="submit" value="is_lower_case" name="submit">Vote</button></form><p></p>--><div class="section double-padded">
<p>Checks if a string is lower case.</p>
<p>Convert the given string to lower case, using <code>str.lower()</code> method and compare it to the original.</p>
<pre class="language-python">def is_lower_case(str):
return str == str.lower()</pre>
<label class="collapse">Show examples</label>
<pre class="language-python">is_lower_case('abc') # True
is_lower_case('a3@$') # True
is_lower_case('Ab4') # False</pre>
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