Merge branch 'master' into master

snippets/byte_size.md

@@ -2,7 +2,7 @@
 
 Returns the length of a string in bytes.
 
-`utf-8` encodes a given string and find its length.
+`utf-8` encodes a given string, then `len` finds the length of the encoded string.
 
 ```python
 def byte_size(string):
@@ -12,4 +12,4 @@ def byte_size(string):
 ```python
 byte_size('😀') # 4
 byte_size('Hello World') # 11
-```
+```

snippets/capitalize.md

@@ -2,7 +2,7 @@
 
 Capitalizes the first letter of a string.
 
-Capitalizes the fist letter of the sring and then adds it with rest of the string. Omit the `lower_rest` parameter to keep the rest of the string intact, or set it to `true` to convert to lowercase.
+Capitalizes the first letter of the string and then adds it with rest of the string. Omit the `lower_rest` parameter to keep the rest of the string intact, or set it to `true` to convert to lowercase.
 
 ```python
 def capitalize(string, lower_rest=False):

snippets/capitalize_every_word.md

@@ -2,7 +2,7 @@
 
 Capitalizes the first letter of every word in a string.
 
-Uses `str.title` to capitalize first letter of evry word in the string.
+Uses `str.title` to capitalize first letter of every word in the string.
 
 ```python
 def capitalize_every_word(string):

snippets/count_occurences.md

@@ -2,7 +2,7 @@
 
 :information_source: Already implemented via `list.count()`.
 
-Counts the occurrences of a value in an list.
+Counts the occurrences of a value in a list.
 
 Uses the list comprehension to increment a counter each time you encounter the specific value inside the list.
 

snippets/count_vowels.md

@@ -7,12 +7,9 @@ Use a regular expression to count the number of vowels `(A, E, I, O, U)` in a st
 ```python
 import re
 
-
 def count_vowels(str):
-    return len(len(re.findall(r'[aeiou]', str, re.IGNORECASE)))
-```
+    return len(re.findall(r'[aeiou]', str, re.IGNORECASE))
 
-``` python
 count_vowels('foobar') # 3
-count_vowels('gym') # 0
+count_vowels('gym')# 0
 ```

snippets/decapitalize.md

@@ -2,7 +2,7 @@
 
 Decapitalizes the first letter of a string.
 
-Decapitalizes the fist letter of the sring and then adds it with rest of the string. Omit the `upper_rest` parameter to keep the rest of the string intact, or set it to `true` to convert to uppercase.
+Decapitalizes the first letter of the string and then adds it with rest of the string. Omit the `upper_rest` parameter to keep the rest of the string intact, or set it to `true` to convert to uppercase.
 
 ```python
 def decapitalize(string, upper_rest=False):

snippets/fermat_test.md

@@ -0,0 +1,33 @@
+### fermat_test
+
+Checks if the number is prime or not. Returns True if passed number is prime, and False if not.
+
+The function uses Fermat's theorem. 
+First, it picks the number `A` in range `1`..`(n-1)`, then it checks if `A` to the power of `n-1` modulo `n` equals `1`. 
+If not, the number is not prime, else it's pseudoprime with probability 1/2. Applying this test `k `times we have probability `1/(2^k)`.
+For example, if the number passes the test `10` times, we have probability `0.00098`.
+
+``` python
+from random import randint
+
+
+def fermat_test(n, k=100):
+    if n <= 1:
+        return False
+    for i in range(k):
+        a = randint(1, n - 1)
+        if pow(a, n - 1, n) != 1:
+            return False
+    return True
+
+```
+
+``` python
+fermat_test(0)  # False
+fermat_test(1)  # False
+fermat_test(561)  # False
+fermat_test(41041)  # False
+fermat_test(17)  # True
+fermat_test(162259276829213363391578010288127)  # True
+fermat_test(-1)  # False
+```

snippets/is_anagram.md

@@ -0,0 +1,20 @@
+### is_anagram
+
+Determine if 2 strings are anagrams.
+
+Returns true if 2 strings are anagrams of each other, false otherwise.
+Capital letters and whitespaces are ignored.
+
+``` python
+def is_anagram(str1, str2):
+    str1, str2 = str1.replace(" ", ""), str2.replace(" ", "")
+
+    if len(str1) != len(str2):
+        return False
+    else:
+        return sorted(str1.lower()) == sorted(str2.lower())
+```
+
+``` python
+is_anagram("anagram", "Nag a ram")  # True
+```

snippets/is_upper_case.md

@@ -11,6 +11,6 @@ def is_upper_case(string):
 
 ```python
 is_upper_case('ABC') # True
-is_upper_case('a3@$') # True
+is_upper_case('a3@$') # False
 is_upper_case('aB4') # False
-```
+```

snippets/keys_only.md

@@ -2,14 +2,11 @@
 
 Function which accepts a dictionary of key value pairs and returns a new flat list of only the keys.
 
-Uses the .items() function with a for loop on the dictionary to track both the key and value and returns a new list by appending the keys to it. Best used on 1 level-deep key:value pair dictionaries (a flat dictionary) and not nested data-structures which are also commonly used with dictionaries. (a flat dictionary resembles a json and a flat list an array for javascript people).
+Uses the .keys() method of "dict" objects. dict.keys() returns a view object that displays a list of all the keys. Then, list(dict.keys()) returns a list that stores all the keys of a dict.
 
 ``` python
 def keys_only(flat_dict):
-    lst = []
-    for k, v in flat_dict.items():
-        lst.append(k)
-    return lst
+    return list(flat_dict.keys())
 ```
 
 ``` python

snippets/zip.md

@@ -12,7 +12,7 @@ def zip(*args, fillvalue=None):
     result = []
     for i in range(max_length):
         result.append([
-            args[k][i] if i < len(args[k]) else None for k in range(len(args))
+            args[k][i] if i < len(args[k]) else fillvalue for k in range(len(args))
         ])
     return result
 ```