Using UTF-8 Encoding in Python Source Code

In certain scenarios, you may encounter errors related to non-ASCII characters when working with Unicode strings in Python source code. This is because the default encoding for Python 2 source files is not UTF-8.

Declaring UTF-8 Strings

In Python 3, UTF-8 is the default source encoding, so you can directly use Unicode characters without any special declaration. However, in Python 2, you need to explicitly declare the UTF-8 encoding in the source file header using the following syntax:

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

Place this line at the beginning of your Python 2 source file.

For example, consider the following Python 2 code:

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

u = 'idzie wąż wąską dróżką'
uu = u.decode('utf8')
s = uu.encode('cp1250')
print(s)

This code uses UTF-8 encoding and successfully converts the Unicode string to a CP1250-encoded byte string for printing.

By declaring UTF-8 encoding, you ensure that Python will interpret the Unicode characters correctly and avoid errors related to non-ASCII characters. It is important to note that this declaration must be placed at the beginning of the source file, before any other code.