pyupgrade_cli_quickstart_python_syntax_upgrade_examples.py

1# pyupgrade is primarily used as a command-line tool or a pre-commit hook.
2# To use it via the command line to upgrade a file to Python 3.8+ syntax:
3
4# 1. Install via pip:
5# pip install pyupgrade
6
7# 2. Run against a file:
8# pyupgrade --py38-plus example.py
9
10# Below is an example of code BEFORE and AFTER running pyupgrade:
11
12# BEFORE:
13def function():
14    # pyupgrade will convert old-style format strings
15    print('hello {}'.format('world'))
16    
17    # pyupgrade will convert old-style type hints in comments
18    x = 1  # type: int
19    
20    # pyupgrade will convert sets/dicts using unnecessary calls
21    y = set([1, 2])
22
23# AFTER (pyupgrade --py311-plus example.py):
24def function():
25    # Converted to f-string
26    print(f'hello {"world"}')
27    
28    # Converted to inline type hint
29    x: int = 1
30    
31    # Converted to literal
32    y = {1, 2}