.join

# example of join() function in python

numList = ['1', '2', '3', '4']
separator = ', '
print(separator.join(numList))

"seperator".join(list/tuple)

# Python program to demonstrate the 
# use of join function to join list 
# elements without any separator. 
  
# Joining with empty separator 
list1 = ['g','e','e','k', 's']  
print("".join(list1)) 

geeks