Create file but if name exists add number

Question

Does Python have any built-in functionality to add a number to a filename if it already exists?

My idea is that it would work the way certain OS\'s work - if a file

Answer 1

I found that the os.path.exists() conditional function did what I needed. I'm using a dictionary-to-csv saving as an example, but the same logic could work for any file type:

import os 

def smart_save(filename, dict):
    od = filename + '_' # added underscore before number for clarity

    for i in np.arange(0,500,1): # I set an arbitrary upper limit of 500
        d = od + str(i)

        if os.path.exists(d + '.csv'):
            pass

        else:
            with open(d + '.csv', 'w') as f: #or any saving operation you need
                for key in dict.keys():
                    f.write("%s,%s\n"%(key, dictionary[key]))
            break

Note: this appends a number (starting at 0) to the file name by default, but it's easy to shift that around.