Just a short python script to convert a file from one encoding to another

file_encoder.py

# coding=utf-8
"""
Convert a file from one encoder to another
    usage: python file_encoder.py 'source encode', 'target encode', 
    'source file', 'target'
    example: python file_encoder.py 'iso8859-1', 'utf-8', 'file.html', 
    'file-utf8.html'
"""

import sys
import codecs

if sys.argv.__len__() != 5:
    print(
        "usage: file_encoder.py 'source encode', 'target encode', "
        "'source file', 'target'  ")
    sys.exit(2)

source_encode = sys.argv[1]  # first parameter is the script itself
target_encode = sys.argv[2]
sourceFileName = sys.argv[3]
targetFileName = sys.argv[4]

BLOCK = 1048576
with codecs.open(sourceFileName, "r", source_encode) as sourceFile:
    with codecs.open(targetFileName, "w", target_encode) as targetFile:
        while True:
            contents = sourceFile.read(BLOCK)
            if not contents:
                break
            targetFile.write(contents)