Word Occurence Script Added (#1576)

* Word Occurence Script Added

* Word Occurence Script Updated

* Added doctest using collections.Counter

https://docs.python.org/3/library/collections.html#collections.Counter

strings/word_occurence.py

@@ -0,0 +1,23 @@
+# Created by sarathkaul on 17/11/19
+from collections import defaultdict
+
+
+def word_occurence(sentence: str) -> dict:
+    """
+    >>> from collections import Counter
+    >>> SENTENCE = "a b A b c b d b d e f e g e h e i e j e 0"
+    >>> occurence_dict = word_occurence(SENTENCE)
+    >>> all(occurence_dict[word] == count for word, count
+    ...     in Counter(SENTENCE.split()).items())
+    True
+    """
+    occurence = defaultdict(int)
+    # Creating a dictionary containing count of each word
+    for word in sentence.split(" "):
+        occurence[word] += 1
+    return occurence
+
+
+if __name__ == "__main__":
+    for word, count in word_occurence("INPUT STRING").items():
+        print(f"{word}: {count}")