Solution Exercise 15: the list of common elements to two lists

Exercise 15

Write a Python program in the form of a Python function which takes two lists as parameters and returns the list of elements common to these two lists.

Solution

def listCommonElements (L1, L2):
     # initialization of the list of common elements
     listCommon = []
 
     # iterate over the elements of L1 and L2 and find the common elements
     for x in L1:
          if x in L2:
               listCommon.append (x)
     return listCommon
 
# Example
L1 = [5, 19, 21, 7, 13, 21]
L2 = [3, 22, 19, 12, 13, 7]
print (listCommonElements (L1, L2)) # The output is: [19, 7, 13]