2.7.5 Assistance

[patrickperea]

Hello I am in need of some assistance, to quickly sum it up I obtain an incoming payment file that is 33 characters long on each line and I need it to be 88 characters on each line with one of the files ending with N (get 4 files in total a day). I wrote the script with no issue with 3.10 using f string but found out the server is 2.7.5 so had to change it to .format instead. The issue that I am running into is the file that is supposed to have the N does not format during conversion but will space it out.

Desired output

AAA N
AAA N

Output I am getting is
AAA
AAA

My code:

import sys

filename=sys.argv[1]
WF = 'Nfile.txt'
suffix='N'
desired_length=87
lines = []


def reformat_file(filename = filename, desired_length = desired_length, suffix = suffix):
  if filename == WF:
    with open(filename, 'r') as fp:
        for line in fp:
            line = line.strip()
            formatted = line
            len(line) < desired_length
            formatted = "{line:{desired_length}}{suffix}".format(line=line, desired_length=desired_length, suffix=suffix)             
            lines.append(formatted)


    return
  else:
    
    with open(filename, 'r') as fp:
        for line in fp:
            line = line.strip()
            formatted = line
            len(line) < desired_length
            formatted = "{line:{desired_length}}".format(line=line, desired_length=desired_length)            
            lines.append(formatted)

    with open(filename, 'w') as fp:
        fp.write('\n'.join(lines))

    return
    
if __name__ == "__main__":
    reformat_file(filename)

I dont know why it defaults to the else in my if statement, any help would be appreciated.