How to create a temporary file with Unicode encoding?
python, temporary-files, unicode
Solution
Everyone else's answers are correct, I just want to clarify what's going on:
The difference between the literal `'foo'` and the literal `u'foo'` is that the former is a string of bytes and the latter is the Unicode object.
First, understand that Unicode is the character set. UTF-8 is the encoding. The Unicode object is the about the former—it's a Unicode string, not necessarily a UTF-8 one. In your case, the encoding for a string literal will be UTF-8, because you specified it in the first lines of the file.
To get a Unicode string from a byte string, you call the `.encode()` method:
>>>> u"ひらがな".encode("utf-8") == "ひらがな"
True
Similarly, you could call your string.encode in the `write` call and achieve the same effect as just removing the `u`.
If you didn't specify the encoding in the top, say if you were reading the Unicode data from another file, you would specify what encoding it was in before it reached a Python string. This would determine how it would be represented in bytes (i.e., the `str` type).
The error you're getting, then, is only because the `tempfile` module is expecting a `str` object. This doesn't mean it can't handle unicode, just that it expects you to pass in a byte string rather than a Unicode object—because without you specifying an encoding, it wouldn't know how to write it to the temp file.
Problem
When I use `open()` to open a file, I am not able to write unicode strings. I have learned that I need to use `codecs` and open the file with Unicode encoding (see http://docs.python.org/howto/unicode.html#reading-and-writing-unicode-data). Now I need to create some temporary files. I tried to use the `tempfile` library, but it doesn't have any encoding option. When I try to write any unicode string in a temporary file with `tempfile`, it fails: ``` #!/usr/bin/python2.6 # -*- coding: utf-8 -*- import tempfile with tempfile.TemporaryFile() as fh: fh.write(u"Hello World: ä") fh.seek(0) for line in fh: print line ``` How can I create a temporary file with Unicode encoding in Python? Edit: I am using Linux and the error message that I get for this code is: ``` Traceback (most recent call last): File "tmp_file.py", line 5, in <module> fh.write(u"Hello World: ä") UnicodeEncodeError: 'ascii' codec can't encode character u'\xe4' in position 13: ordinal not in range(128) ``` - This is just an example. In practice I am trying to write a string that some API returned.