Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Should I use encoding declaration in Python 3?

People also ask

What encoding should I use Python?

UTF-8 is one of the most commonly used encodings, and Python often defaults to using it. UTF stands for “Unicode Transformation Format”, and the '8' means that 8-bit values are used in the encoding. (There are also UTF-16 and UTF-32 encodings, but they are less frequently used than UTF-8.)

What is the default encoding in python3?

By default in Python 3, we are on the left side in the world of Unicode code points for strings. We only need to go back and forth with bytes while writing or reading the data. Default encoding during this conversion is UTF-8, but other encodings can also be used.

Why is UTF-8 a good choice for the default editor encoding in Python?

As a content author or developer, you should nowadays always choose the UTF-8 character encoding for your content or data. This Unicode encoding is a good choice because you can use a single character encoding to handle any character you are likely to need. This greatly simplifies things.

What is encoding in Python file handling?

The encoding information is then used by the Python parser to interpret the file using the given encoding. Most notably this enhances the interpretation of Unicode literals in the source code and makes it possible to write Unicode literals using e.g. UTF-8 directly in an Unicode aware editor.


Because the default is UTF-8, you only need to use that declaration when you deviate from the default, or if you rely on other tools (like your IDE or text editor) to make use of that information.

In other words, as far as Python is concerned, only when you want to use an encoding that differs do you have to use that declaration.

Other tools, such as your editor, can support similar syntax, which is why the PEP 263 specification allows for considerable flexibility in the syntax (it must be a comment, the text coding must be there, followed by either a : or = character and optional whitespace, followed by a recognised codec).

Note that it only applies to how Python reads the source code. It doesn't apply to executing that code, so not to how printing, opening files, or any other I/O operations translate between bytes and Unicode. For more details on Python, Unicode, and encodings, I strongly urge you to read the Python Unicode HOWTO, or the very thorough Pragmatic Unicode talk by Ned Batchelder.


No, if:

  • entire project use only the UTF-8, which is a default.
  • and you're sure your IDE tool doesn't need that encoding declaration in each file.

Yes, if

  • your project relies on different encoding
  • or relies on many encodings.

For multi-encodings projects:

If some files are encoded in the non-utf-8, then even for these encoded in UTF-8 you should add encoding declaration too, because the golden rule is Explicit is better than implicit.

Reference:

  • PyCharm doesn't need that declaration:

configuring encoding for specific file in pycharm

  • vim doesn't need that declaration, but:
# vim: set fileencoding=<encoding name> :