How to determine the encoding of text?

Nope picture Nope · Jan 12, 2009 · Viewed 251.2k times · Source

I received some text that is encoded, but I don't know what charset was used. Is there a way to determine the encoding of a text file using Python? How can I detect the encoding/codepage of a text file deals with C#.

Answer

nosklo picture nosklo · Jan 12, 2009

Correctly detecting the encoding all times is impossible.

(From chardet FAQ:)

However, some encodings are optimized for specific languages, and languages are not random. Some character sequences pop up all the time, while other sequences make no sense. A person fluent in English who opens a newspaper and finds “txzqJv 2!dasd0a QqdKjvz” will instantly recognize that that isn't English (even though it is composed entirely of English letters). By studying lots of “typical” text, a computer algorithm can simulate this kind of fluency and make an educated guess about a text's language.

There is the chardet library that uses that study to try to detect encoding. chardet is a port of the auto-detection code in Mozilla.

You can also use UnicodeDammit. It will try the following methods:

  • An encoding discovered in the document itself: for instance, in an XML declaration or (for HTML documents) an http-equiv META tag. If Beautiful Soup finds this kind of encoding within the document, it parses the document again from the beginning and gives the new encoding a try. The only exception is if you explicitly specified an encoding, and that encoding actually worked: then it will ignore any encoding it finds in the document.
  • An encoding sniffed by looking at the first few bytes of the file. If an encoding is detected at this stage, it will be one of the UTF-* encodings, EBCDIC, or ASCII.
  • An encoding sniffed by the chardet library, if you have it installed.
  • UTF-8
  • Windows-1252