Python：无法写入文件-UnicodeEncodeError

Question

This code should write some text to file. When I'm trying to write my text to console, everything works. But when I try to write the text into the file, I get UnicodeEncodeError. I know, that this is a common problem which can be solved using proper decode or encode, but I tried it and still getting the same UnicodeEncodeError. What am I doing wrong?

I've attached an example.

print "(%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)".decode("utf-8")%(dict.get('name'),dict.get('description'),dict.get('ico'),dict.get('city'),dict.get('ulCislo'),dict.get('psc'),dict.get('weby'),dict.get('telefony'),dict.get('mobily'),dict.get('faxy'),dict.get('emaily'),dict.get('dic'),dict.get('ic_dph'),dict.get('kategorie')[0],dict.get('kategorie')[1],dict.get('kategorie')[2])

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with open("test.txt","wb") as f:
   f.write("(%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)".decode("utf-8")%(dict.get('name'),dict.get('description'),dict.get('ico'),dict.get('city'),dict.get('ulCislo'),dict.get('psc'),dict.get('weby'),dict.get('telefony'),dict.get('mobily'),dict.get('faxy'),dict.get('emaily'),dict.get('dic'),dict.get('ic_dph'),dict.get('kategorie')[0],dict.get('kategorie')[1],dict.get('kategorie')[2]))

UnicodeEncodeError: 'ascii' codec can't encode character u'\č' in position 50: ordinal not in range(128)

Where could be the problem?

Answer 1

To write Unicode text to a file, you could use io.open() function :

#!/usr/bin/env python
from io import open

with open('utf8.txt', 'w', encoding='utf-8') as file:
    file.write(u'\u010d')

It is default on Python 3.

Note: you should not use the binary file mode ( 'b' ) if you want to write text.

# coding: utf8 that defines the source code encoding has nothing to do with it.

If you see sys.setdefaultencoding() outside of site.py or Python tests; assume the code is broken.

Answer 2

@ned-batchelder is right. You have to declare that the system default encoding is "utf-8". The coding comment # -*- coding: utf-8 -*- doesn't do this.

To declare the system default encoding, you have to import the module sys , and call sys.setdefaultencoding('utf-8') . However, sys was previously imported by the system and its setdefaultencoding method was removed. So you have to reload it before you call the method.

So, you will need to add the following codes at the beginning:

import sys
reload(sys)
sys.setdefaultencoding('utf-8')

Answer 3

You may need to explicitly declare that python use UTF-8 encoding.

The answer to this SO question explains how to do that: Declaring Encoding in Python

Answer 4

For Python 2:

1. Declare document encoding on top of the file (if not done yet):

   # -*- coding: utf-8 -*-

2. Replace .decode with .encode :

    with open("test.txt","wb") as f: f.write("(%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)".encode("utf-8")%(dict.get('name'),dict.get('description'),dict.get('ico'),dict.get('city'),dict.get('ulCislo'),dict.get('psc'),dict.get('weby'),dict.get('telefony'),dict.get('mobily'),dict.get('faxy'),dict.get('emaily'),dict.get('dic'),dict.get('ic_dph'),dict.get('kategorie')[0],dict.get('kategorie')[1],dict.get('kategorie')[2]))