Python Read Torrent Size / 讀取BT檔案的大小

因為某些情況下,不想常常使用軟件來打開種子查看大小.
所以就寫了這個小程式,當中使用了別人寫的 decoder 檔案.
所以寫起來比較輕鬆..記錄一下

#!/usr/bin/python
# -*- coding: utf-8 -*-
#=========================================
split_line_length = 80
#=========================================
__version__ = "0.0.1 Beta"
__author__ = "Zeuxis Lo"
__datetime__ = "201005312313"
__appname__ = "Torrent File Total Size(Python)"

import sys, getopt, decoder, time

def get_size_fromat(n):
    K, M, G, T = 1 << 10, 1 << 20, 1 << 30, 1 << 40
    if   n >= T:
        return '%.2f T' % (float(n) / T)
    elif n >= G:
        return '%.2f G' % (float(n) / G)
    elif n >= M:
        return '%.2f M' % (float(n) / M)
    elif n >= K:
        return '%.2f K' % (float(n) / K)
    else:
        return '%.2f B' % n

def main(argv=None):
    if argv is None:
        argv = sys.argv

	if len(argv) == 2:
		data = decoder.decode(open(argv[1], "rb").read())

		#data.keys()
		print "%-25s" % ("-" * split_line_length)
		print "%-14s | %s" % ("Size", "File Name")
		print "%-25s" % ("-" * split_line_length)
		
		total_size = 0
		for file in data["info"]["files"]:
			path = "/".join(file["path"])
			length = file["length"]
			if path[:5] != "_____":
				total_size += length
				print "%14s | %s" % (get_size_fromat(length), path.decode(data["encoding"]).encode("big5"))
				
		print "%-25s" % ("-" * split_line_length)
		print "Total Size: %s" % get_size_fromat(total_size)
		print "%-25s" % ("-" * split_line_length)
		
		time.sleep(1)
		sys.exit()
	else:
		print "python torrent_size.py [file name]"
		return 2
		
if __name__ == "__main__":
    sys.exit(main())

import re

def tokenize(text, match=re.compile("([idel])|(\d+):|(-?\d+)").match):
    i = 0
    while i < len(text):
        m = match(text, i)
        s = m.group(m.lastindex)
        i = m.end()
        if m.lastindex == 2:
            yield "s"
            yield text[i:i+int(s)]
            i = i + int(s)
        else:
            yield s

def decode_item(next, token):
    if token == "i":
        # integer: "i" value "e"
        data = int(next())
        if next() != "e":
            raise ValueError
    elif token == "s":
        # string: "s" value (virtual tokens)
        data = next()
    elif token == "l" or token == "d":
        # container: "l" (or "d") values "e"
        data = []
        tok = next()
        while tok != "e":
            data.append(decode_item(next, tok))
            tok = next()
        if token == "d":
            data = dict(zip(data[0::2], data[1::2]))
    else:
        raise ValueError
    return data

def decode(text):
    try:
        src = tokenize(text)
        data = decode_item(src.next, src.next())
        for token in src: # look for more tokens
            raise SyntaxError("trailing junk")
    except (AttributeError, ValueError, StopIteration):
        raise SyntaxError("syntax error")
    return data