how make python script for renewable downloads?
Question: I've been searching (without results) a reanudable (i don't know if this is
the correct word, sorry) way to download big files from internet with python,
i know how do it directly with urllib2, but if something interrupt the
connection, i need some way to reconnect and continue the download where it
was if it's possible (like a download manager).


Answer: For other people who can help the answer, there's a HTTP protocol called
Chunked Transfer Encoding that allow to do this specifying the 'Range' header
of the request with the beginning and end bytes (separated by a dash), thus is
possible just count how many bytes was downloaded previously and send it like
the new beginning byte for continue the download. Example with requests
module:

    
    
    import requests
    from os.path import getsize
    
    #get size of previous downloaded chunk file
    beg = getsize(PATH_TO_FILE)
    #if we want we can get the size before download the file (without actually download it)
    end = request.head(URL).headers['content-length']
    #continue the download in the next byte from where it stopped
    headers = {'Range': "bytes=%d-%s"%(beg+1,end)}
    download = requests.get(URL, headers=headers)
    

