Python File Renaming

Question

I have some files in a directory,

file_IL.txt
file_IL.csv
file_NY.txt
file_NY.csv

I will have to rename them so that they get a sequence number.

Answer 1

The best approach is to store the extension and count for that extension in a dictionary.

def __call__(self):  

    found = glob.glob(self.indir + '/file*')  
    length = len(found)  
    counts = {}

    for num in found:
        ext = num.rsplit(".",1)[-1]    # Right split to get the extension
        count = counts.get(ext,0) + 1  # get the count, or the default of 0 and add 1
        shutil.copy(num, num+'_'+'%03d' % count)   # Fill to 3 zeros
        counts[ext] = count            # Store the new count