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/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(re.findall(r'[aeiou]', str, re.IGNORECASE))
-```
 
-``` python
-count_vowels('foobar')  # 3
-count_vowels('gym')  # 0
+count_vowels('foobar') # 3
+count_vowels('gym')# 0
 ```

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
 ```