task1-3

import re

str1 = "Welcome to _CEICData. Welcome to BPA; Wecome to ISI"

str1_list = re.split(r'[;,._ ]', str1)

while "" in str1_list:

    str1_list.remove('')

for x in str1_list:

    if len(x)>4:

        x_list = list(x)

        x_list[4:len(x)] = "."*(len(x)-4)

        x_list = ''.join(x_list)

        print(x_list,end=" , ")

    else:

        print(x,end=" , ")