How do you replace a word after a match from a list of words in each line of a file?

[vijju56]

We are looking for replacing a word after each match in a list of words for each line in a file

This is Manager Sam speaking.Hello, how are you? I am Fine. this is Director Tom. Nice to Meet you Manager Sam.

import re
f1=open('testinput.txt', 'r')
f2=open('testoutput.txt', 'w')
checkWords = ["Manager","Director"]
repWords = ("*** ")

for line in f1:
    i = 0
    for i in range(len(checkWords)):
        # Find the next word after the search word
        list1 = re.compile(r'%s\s+((?:\w+(?:\s+!$)) {1})' %checkWords[i]).findall(line)
        checkWords = ','.join(list1)
        print(checkWords)
        line = line.replace(checkWords, repWords)
        print(line)
        f2.write(line)
f1.close()
f2.close()

Output:
Expected Output:

This is Manager * speaking.Hello, how are you? I am Fine. this is Director * Nice to Meet you Manager ***

But, Output I am getting now: * T* h*** i*** s*** * i* s*** * M* a*** n*** a*** g*** e*** r*** * S* a*** m*** * s* p*** e*** a*** k*** i*** n*** g*** .* H* e*** l*** l*** o*** ,* * h*** o*** w*** * a* r*** e*** * y* o*** u*** ?***

[baquerik]

Hello vijjuu,

there are so many stars in your output because this line of code returns nothing and every character is then a match

list1 = re.compile(r'%s\s+((?:\w+(?:\s+!$)) {1})' %checkWords[i]).findall(line)

There must be way better ways of doing this, but this code gives the output you were asking for:

f1=open('testinput.txt', 'r')
f2=open('testoutput.txt', 'w')
checkWords = ["Manager","Director"]
repWords = ("*")
 
for line in f1:
    words = line.split(" ")
    for i in range(len(words)):
        for checkword in checkWords:
            if words[i] == checkword:
            	words[i+1] = repWords
    newline = ""
    for word in words:
        newline = newline + word + " "
    print(newline)
    f2.write(newline)
f1.close()
f2.close()

Output:
This is Manager * speaking.Hello, how are you? I am Fine. this is Director * Nice to Meet you Manager *

Problems: It does not "understand" what a word is, so if punctuation symbols are involved (in the matched word or in the replacement) it fails.