finding the last file created in a directory

[Petr Man]

Hello everyone,
I have a repeatedly running process, which always creates a new logfile with
an ending n+1. What I need is to find the last file, the one with highest
number at the end. The problem is, that the max() method gives me a wrong
answer. I tried to convert the items in my list into integers using int(),
but that ends up with an error ValueError: invalid literal for int():

My code currently looks like this:

def get_logfile(dir, file_name):
new_file_name = file_name[:-3] + 'log'
listing = glob.glob(dir + new_file_name + '*')
numbers = []
for i in range(len(listing)):
item = listing[i]
numbers.append(item[len(dir) + len(new_file_name) + 1:])
return new_file_name + '.' + max(numbers)
cheers

Petr