get_duplicates_python3v2

a = [1,1,2,3,5,8,13,21,34,55,89]
b = [i for i in range(1,14)]    # generating a list of numbers with list comprehension

# Defining a function that takes 2 lists as arguments and returns 1 list.
# Functions allow us to use the same code multiple times with very little changes.
def get_duplicates(first_list, second_list):
    # set(a+b) is a list of all values (without duplications
    # notice the use of 'if' statement and 'and' operator inside the list comprehension
    list_of_duplicates = [i for i in set(first_list+second_list) if i in first_list and i in second_list]
    # returning the list for allowing future use.
    return list_of_duplicates


# Now we can use our function multiple times, in multiple ways.
print('first list:',a)
print('second list:',b)
print('\nGetting duplicates from both list:')
print(get_duplicates(a,b))


# Lets use our function with some other list:
c = [i for i in range(30,90,5)]
print('\nnew list c:', c)
print('Getting duplicates from new list:')
print(get_duplicates(a,c))