find common elements in one list python code example

Example 1: find common elements in two lists python

list1 = [1,2,3,4,5,6]
list2 = [3, 5, 7, 9]
list(set(list1).intersection(list2))

Example 2: find number of common element in two python array

len([x for x in list1 if x in list2])

Example 3: most common elements in a list python

>>> # Tally occurrences of words in a list
>>> cnt = Counter()
>>> for word in ['red', 'blue', 'red', 'green', 'blue', 'blue']:
...     cnt[word] += 1
>>> cnt
Counter({'blue': 3, 'red': 2, 'green': 1})

>>> # Find the ten most common words in Hamlet
>>> import re
>>> words = re.findall(r'\w+', open('hamlet.txt').read().lower())
>>> Counter(words).most_common(10)
[('the', 1143), ('and', 966), ('to', 762), ('of', 669), ('i', 631),
 ('you', 554),  ('a', 546), ('my', 514), ('hamlet', 471), ('in', 451)]