fix: space count in strings/word_occurrence.py (TheAlgorithms#1896)

* fix: space count in strings/word_occurrence.py

* Update strings/word_occurrence.py

Co-Authored-By: Christian Clauss <cclauss@me.com>

* Update strings/word_occurrence.py

Co-Authored-By: Christian Clauss <cclauss@me.com>

* Update strings/word_occurrence.py

Co-Authored-By: Christian Clauss <cclauss@me.com>

* Update word_occurrence.py

Seems like, there is no need o `occurrence.pop('', None)`

Co-authored-by: Christian Clauss <cclauss@me.com>

Author: darkmatter18

strings/word_occurrence.py

@@ -1,4 +1,5 @@
 # Created by sarathkaul on 17/11/19
+# Modified by Arkadip Bhattacharya(@darkmatter18) on 20/04/2020
 from collections import defaultdict
 
 
@@ -10,10 +11,12 @@ def word_occurence(sentence: str) -> dict:
     >>> all(occurence_dict[word] == count for word, count
     ...     in Counter(SENTENCE.split()).items())
     True
+    >>> dict(word_occurence("Two  spaces"))
+    {'Two': 1, 'spaces': 1}
     """
     occurrence = defaultdict(int)
     # Creating a dictionary containing count of each word
-    for word in sentence.split(" "):
+    for word in sentence.split():
         occurrence[word] += 1
     return occurrence