Adding line numbers to a file in python 3

Question

I need to write the line numbers to an already existing text file in python 3. They have asked for the first 5 columns of the text file to contain a 4 digit line number foll

Answer 1

#!/usr/bin/python
numberedfile = open("test.txt", "r")
numberedlist = numberedfile.readline()
i = 0
for lines in numberdlist:
    i = i+1
    print str(i) + '\t' + lines
numberdfile.close()