Python, trying to get file extension via URL

Question

I'm making an image grabber for the puush service; however, whenever I generate a random URL and attempt to verify it as a .PNG image, an error is generated. I just took up the Python language earlier today, so you could say I'm very new to this!

The error that is generated:

Traceback (most recent call last):
  File "run.py", line 19, in <module>
    extension = guess_extension(guess_type(url))
  File "C:\Python33\lib\mimetypes.py", line 320, in guess_extension
    return _db.guess_extension(type, strict)
  File "C:\Python33\lib\mimetypes.py", line 189, in guess_extension
    extensions = self.guess_all_extensions(type, strict)
  File "C:\Python33\lib\mimetypes.py", line 168, in guess_all_extensions
    type = type.lower()
AttributeError: 'tuple' object has no attribute 'lower'

The code that is ran:

#!/usr/bin/env python
import sys
import urllib
from mimetypes import guess_type, guess_extension
from random import choice

randoms = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
           'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I',' J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
           '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];

downloads = 1;

#the number of files we want to download
target = int(sys.argv[1]);

while downloads <= target:
    string = choice(randoms)+choice(randoms)+choice(randoms)+choice(randoms)+choice(randoms)
    url = 'http://puu.sh/'+string

    print(str(downloads)+': '+string)

    #download
    extension = guess_extension(guess_type(url))
    print(extension)

    #urllib.request('http://puu.sh/'+string, string+'.png')
    downloads += 1

Any ideas on what this error is attempting to tell me? Thanks.

Answer 1

guess_type() returns a tuple (type,encoding), whereas guess_extension() accepts a single argument type.

The line

extension = guess_extension(guess_type(url))

calls guess_type and then passes its return value (tuple) to guess_extension. You should only pass the first element of the tuple (type)

extension = guess_extension(guess_type(url)[0])