📦 dirty-equals/ samuelcolvin

Usage

Here's a trivial example of what dirty-equals can do:

from dirty_equals import IsPositive

assert 1 == IsPositive
assert -2 == IsPositive  # this will fail!

That doesn't look very useful yet!, but consider the following unit test code using dirty-equals:

from dirty_equals import IsJson, IsNow, IsPositiveInt, IsStr

...

# user_data is a dict returned from a database or API which we want to test
assert user_data == {
    # we want to check that id is a positive int
    'id': IsPositiveInt,
    # we know avatar_file should be a string, but we need a regex as we don't know whole value
    'avatar_file': IsStr(regex=r'/[a-z0-9\-]{10}/example\.png'),
    # settings_json is JSON, but it's more robust to compare the value it encodes, not strings
    'settings_json': IsJson({'theme': 'dark', 'language': 'en'}),
    # created_ts is datetime, we don't know the exact value, but we know it should be close to now
    'created_ts': IsNow(delta=3),
}

Without dirty-equals, you'd have to compare individual fields and/or modify some fields before comparison - the test would not be declarative or as clear.

dirty-equals can do so much more than that, for example:

…

Installation

Simply:

pip install dirty-equals

dirty-equals requires Python 3.9+.