python strip function is not giving expected output

Question

i have below code in which filenames are FR1.1.csv, FR2.0.csv etc. I am using these names to print in header row but i want to modify these name to FR1.1 , Fr2.0 and so on. Hence i am using strip function to remove .csv. when i have tried it at command prompt its working fine. But when i have added it to main script its not giving output.

for fname in filenames:
    print "fname     : ", fname
    fname.strip('.csv');
    print "after strip fname: ", fname
    headerline.append(fname+' Compile');
    headerline.append(fname+' Run');

output i am getting

fname     :FR1.1.csv
after strip fname: FR1.1.csv

required output-->

fname     :FR1.1.csv
after strip fname: FR1.1

i guess some indentation problem is there in my code after for loop. plesae tell me what is the correct way to achive this.

Answer 1

Strings are immutable, so string methods can't change the original string, they return a new one which you need to assign again:

fname = fname.strip('.csv')   # no semicolons in Python!

But this call doesn't do what you probably expect it to. It will remove all the leading and trailing characters c, s, v and . from your string:

>>> "cross.csv".strip(".csv")
'ro'

So you probably want to do

import re
fname = re.sub(r"\.csv$", "", fname)