CODEWITHSUNDEEP
pythonpython-2.7operating-system
Mojimi
Mojimi

Reputation: 3161

String to Integer error on file name

I'm trying to add 59 to the 3 digits in a specific position in all the files in my folder, but it gives this error:

ValueError: invalid literal for int() with base 10: ''

I have checked with prints, and is indeed a 3 char string, containing only digits(by the looks)

Code :

import os

def left(s, amount):
        return s[:amount]

def right(s, amount):
        return s[-amount:]

def mid(s, offset, amount):
        return s[offset:offset+amount]


for filename in os.listdir("V:\HD_RASTER\CTA2-GUA3"):
        s = mid(filename, 21, 3)
        print("Chars : " + len(s) + " String : " + s)
        s = int(s) + 59
        s = string(s)   
        os.rename(filename,left(filename,21) +  s + mid(filename,24,len(filename))

Folder screenshot of file names :

enter image description here

Upvotes: 1

Views: 303

Answers (1)

kdopen
kdopen

Reputation: 8215

Your code is very fragile, and functions like left, mid, and right suggest you are more used to another language.

Among other things, this only works if your current directory contains the files, because listdir only returns the file name, not it's path. So os.rename will fail.

Try making it a little more flexible and bulletproof.

import glob
import os

FPATH = r"V:\HD_RASTER\CTA2-GUA3"
FILE_PREFIX= 'TRANS_leilao-004-14_0'
FULL_PREFIX = os.path.join(FPATH,PREFIX)
PREFIX_LEN = len(FULL_PREFIX)

files = glob.glob(FULL_PREFIX+r"???.*")
for old_file in files:
    n = old_file[PREFIX_LEN:PREFIX_LEN+3]
    try:
        new_n = int(n) + 59
    except ValueError:
        print "Failed to parse filename: " + old_file
        continue
    new_file = old_file[:PREFIX_LEN] + str(new_n) + old_file[PREFIX_LEN+3:]
    try:
        os.rename(old_file, new_file)
    catch OSError:
        print "failed to rename " + old_file

Upvotes: 1

Related Questions