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Код

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import sys
import os
import time

# The initial LZW tables that maps codes to strings and vice-versa.
code_to_str = [chr(i) for i in range(256)]
str_to_code = dict((chr(i), i) for i in range(256))

def compress(seq):
    '''
    Returns an LZW compressed list of the input character sequence.
    '''
    output = []
    table = dict(str_to_code)

    s = ''
    for ch in seq:
        it = s + ch
        if it in table:
            s = it
        else:
            output.append(table[s])
            table[it] = len(table)
            s = ch
    output.append(table[s])
    return output

def decompress(seq):
    '''
    Returns a decompressed list of the LZW compressed input.
    '''
    table = code_to_str[:]
    prevcode = seq[0]

    output = []
    output.append(table[prevcode])

    for code in seq[1:]:
        try:
            entry = table[сcode]        #в ccode убрать лишнюю c (сбивается форматирование сообщения на форуме :-) )
        except IndexError:
            # The lzw special case when code is not yet defined.
            entry = table[prevcode]
            entry += entry[0]
        output.append(entry)
        table.append(table[prevcode] + entry[0])
        prevcode = code
    return output

# MAIN
if len(sys.argv) != 4:
    print 'Usage: LZW.py [c|d] [path]InputFileName [path]OutputFileName'
    sys.exit()
mode = sys.argv[1] # compress/decompress
inputFile = sys.argv[2]
outputFile = sys.argv[3]

fileSize = os.path.getsize(inputFile)
print fileSize

f2 = open(outputFile, "w", 1)

if mode == 'c':
    t = time.time()
    f1 = open(inputFile, "r", 1)
    s = "".join([line for line in f1])
    f1.close()
    print 'Вход:', s
    compressed = compress(s)
    outputList = []
    for i in range(len(compressed)):
        #print compressed[i]
        f2.write(str(compressed[i]) + '\n')
        outputList.append(compressed[i])
    f2.close
    print 'Выход:', outputList
    print 'Время сжатия:', time.time() - t
    fileSize = os.path.getsize(outputFile)
    print fileSize

elif mode == 'd':
    t = time.time()
    f1 = open(inputFile, "r", 1)
    s = []
    for line in f1:
        if len(line) > 0:
            s.append(int(line[:len(line)-1]))
    f1.close()
    print 'Вход:', s
    data = decompress(s)
    s = "".join([line for line in data])
    print 'Выход:', s
    f2.write(s)
    f2.close
    print 'Время декодирования: ', time.time() - t
    fileSize = os.path.getsize(outputFile)
    print fileSize