python 3 concatenate strings 2020 code example

Example 1: python merge strings

my_list = ['a', 'b', 'c', 'd']
my_string = ','.join(my_list)
# Output = 'a,b,c,d'

Example 2: python join string with common string

def merge(s1, s2):
    i = 0
    while not s2.startswith(s1[i:]):
        i += 1
    return s1[:i] + s2