Download a file with timeouts

download_file.py

import urllib.request
import urllib.error
import signal

class NoMoreBufferException(Exception):
    pass

class TimesUpException(Exception):
    pass

def handler(signum, frame):
    raise TimesUpException("Download timed out")

def download_block(u, f, block_size):
    buffer = u.read(block_size)
    if not buffer:
        raise NoMoreBufferException("No more to download")
    f.write(buffer)

def download_file(abspath, url):
    '''Download function with block time outs'''
    try:
        u = urllib.request.urlopen(url)
    except urllib.error.HTTPError as e:
        return False
    except:
        return False

    signal.signal(signal.SIGALRM, handler)
    f = open(abspath, "wb")

    block_size = 8192
    while True:
        signal.alarm(60)
        try:
            download_block(u, f, block_size)
        except NoMoreBufferException as e:
            outcome = True
            f.close()
            break
        except TimesUpException as e:
            outcome = False
            f.close()
            delete_file(abspath)
            break

    signal.alarm(0)
    signal.signal(signal.SIGALRM, signal.SIG_DFL)

    return outcome