all Python 3codecsfunction

codecs.EncodedFile()

stream codecs

Wraps a binary file in a StreamRecoder for on-the-fly transcoding: bytes in one encoding outside, bytes in another inside the file.

Syntax

codecs.EncodedFile(file, data_encoding, file_encoding=None, errors='strict')

The trap is the direction: both writing and reading use bytes, not strings, so write('text') raises TypeError and you need write('text'.encode('utf-8')). data_encoding is the encoding of the bytes on your side, file_encoding the one in the file. Closing the wrapper closes the underlying file. The everyday job 'read cp1251, save as UTF-8' is simpler with two open calls and encoding.

Examples

import codecs, io
raw = io.BytesIO('ёж'.encode('cp1251'))
f = codecs.EncodedFile(raw, data_encoding='utf-8', file_encoding='cp1251')
print(f.read())  # → b'\xd1\x91\xd0\xb6' — уже UTF-8
try:
    f.write('ёж')
except TypeError:
    print('нужны bytes')  # → нужны bytes

See also

Common errors

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