Create file but if name exists add number

I was trying to implement the same thing in my project but @unutbu's answer seemed too 'heavy' for my needs so I came up with following code finally:

import os
index = ''
while True:
    try:
        os.makedirs('../hi'+index)
        break
    except WindowsError:
        if index:
            index = '('+str(int(index[1:-1])+1)+')' # Append 1 to number in brackets
        else:
            index = '(1)'
        pass # Go and try create file again

Just in case someone stumbled upon this and requires something simpler.


In a way, Python has this functionality built into the tempfile module. Unfortunately, you have to tap into a private global variable, tempfile._name_sequence. This means that officially, tempfile makes no guarantee that in future versions _name_sequence even exists -- it is an implementation detail. But if you are okay with using it anyway, this shows how you can create uniquely named files of the form file#.pdf in a specified directory such as /tmp:

import tempfile
import itertools as IT
import os

def uniquify(path, sep = ''):
    def name_sequence():
        count = IT.count()
        yield ''
        while True:
            yield '{s}{n:d}'.format(s = sep, n = next(count))
    orig = tempfile._name_sequence 
    with tempfile._once_lock:
        tempfile._name_sequence = name_sequence()
        path = os.path.normpath(path)
        dirname, basename = os.path.split(path)
        filename, ext = os.path.splitext(basename)
        fd, filename = tempfile.mkstemp(dir = dirname, prefix = filename, suffix = ext)
        tempfile._name_sequence = orig
    return filename

print(uniquify('/tmp/file.pdf'))

I ended up writing my own simple function for this. Primitive, but gets the job done:

def uniquify(path):
    filename, extension = os.path.splitext(path)
    counter = 1

    while os.path.exists(path):
        path = filename + " (" + str(counter) + ")" + extension
        counter += 1

    return path