Question

I cant seem to figure out why I keep getting this buggy output.

Input file:

ff1
ff2
ff3
ff10
ff11
ff20
ff21
ff23
gb20
gb10
gh23

Output File:

FF01
FF02
FF03
FF010
FF011
FF020
FF021
FF023
GB020
GB010
GH023

Code:

import os
import sys

#directory is the directory we will work from
directory = "C:\\Users\\user\\Desktop"
os.chdir(directory)

renameWhat = ["ff", "gb", "gh"]

oldFile = open("New Text Document.txt")
buffer = oldFile.read()

for item in renameWhat:
    for i in range(0, 50):
        if i < 10:
            buffer = buffer.replace(item + str(i), item.upper() + "0" + str(i))
        else:
            buffer = buffer.replace(item + str(i), item.upper() + str(i))

outFile = open("test.txt", "w")
outFile.write(buffer)
outFile.close()
oldFile.close()

What needs to happen:

I’m trying to replace ff to uppercase (done), then I need to add zero’s to all numbers that are less than or equal to 9. So I think that if i is less than 10 should be good enough; but it’s not because it’s adding zeroes to everything over 9. I have tried with len(str(i)) to make sure it’s only of length one, but that still does not work; what am I missing?

Answer 1

The reason your original solution doesn’t work is that it isn’t checking that it’s matching a whole line/word/number. So for instance after replacing ff1 with FF01 your buffer is now:

FF01
ff2
ff3
FF010
FF011
ff20
ff21
ff23
gb20
gb10
gh23