如何在Python中将文件转换为utf-8？

Question

我需要用Python把一堆文件转换成utf-8，而我在“转换文件”部分遇到了麻烦。

我想做相当于：

iconv -t utf-8 $file > converted/$file # this is shell code

谢谢！

Answer 1

在一次小测试中，这对我很有用：

sourceEncoding = "iso-8859-1"
targetEncoding = "utf-8"
source = open("source")
target = open("target", "w")

target.write(unicode(source.read(), sourceEncoding).encode(targetEncoding))

Answer 2

您可以使用codecs module，如下所示：

import codecs
BLOCKSIZE = 1048576 # or some other, desired size in bytes
with codecs.open(sourceFileName, "r", "your-source-encoding") as sourceFile:
    with codecs.open(targetFileName, "w", "utf-8") as targetFile:
        while True:
            contents = sourceFile.read(BLOCKSIZE)
            if not contents:
                break
            targetFile.write(contents)

编辑：添加了BLOCKSIZE参数来控制文件块大小。

Answer 3

谢谢你的回复，很管用！

由于源文件是混合格式，我添加了一个按顺序尝试的源格式列表（sourceFormats），并在UnicodeDecodeError上尝试下一种格式：

from __future__ import with_statement

import os
import sys
import codecs
from chardet.universaldetector import UniversalDetector

targetFormat = 'utf-8'
outputDir = 'converted'
detector = UniversalDetector()

def get_encoding_type(current_file):
    detector.reset()
    for line in file(current_file):
        detector.feed(line)
        if detector.done: break
    detector.close()
    return detector.result['encoding']

def convertFileBestGuess(filename):
   sourceFormats = ['ascii', 'iso-8859-1']
   for format in sourceFormats:
     try:
        with codecs.open(fileName, 'rU', format) as sourceFile:
            writeConversion(sourceFile)
            print('Done.')
            return
      except UnicodeDecodeError:
        pass

def convertFileWithDetection(fileName):
    print("Converting '" + fileName + "'...")
    format=get_encoding_type(fileName)
    try:
        with codecs.open(fileName, 'rU', format) as sourceFile:
            writeConversion(sourceFile)
            print('Done.')
            return
    except UnicodeDecodeError:
        pass

    print("Error: failed to convert '" + fileName + "'.")


def writeConversion(file):
    with codecs.open(outputDir + '/' + fileName, 'w', targetFormat) as targetFile:
        for line in file:
            targetFile.write(line)

# Off topic: get the file list and call convertFile on each file
# ...

（由Rudro Badhon编辑：这合并了原来的try多种格式，直到您没有得到异常以及使用chardet.universaldetector的替代方法）