Dirty Equals

0.11.0 · active · verified Fri Apr 10

dirty-equals is a Python library for doing 'dirty' (but useful) things with equality comparisons. It allows for flexible assertions in tests and other contexts, such as comparing values against types, regular expressions, or fuzzy time ranges. The current version is 0.11.0, and the library maintains an active release cadence, with major updates typically every few months.

Warnings

breaking Python 3.8 support was dropped in version 0.10.0. dirty-equals now requires Python 3.9 or newer.
Fix: Upgrade your Python environment to 3.9 or higher if you need to use dirty-equals 0.10.0+.
gotcha The v0.7.0 release was announced but never published to PyPI. Users attempting to install or reference v0.7.0 will fail. The intended changes were included in v0.7.1.
Fix: Use version 0.7.1 or later instead of 0.7.0.
gotcha `IsNow` compares against the *current* moment of time when the assertion runs, not against a specific pre-defined timestamp. This is suitable for fuzzy time comparisons but not for exact matches against a fixed reference.
Fix: Understand that `IsNow()` is dynamic. If you need to compare against a specific historical timestamp, you might need a different approach or to capture `datetime.now()` precisely when creating your expected value.
gotcha Comparison of nested dataclasses was fixed in version 0.11.0. Older versions might exhibit unexpected behavior or failures when comparing complex nested dataclass structures.
Fix: Ensure you are using dirty-equals v0.11.0 or newer when comparing nested dataclass objects to avoid subtle comparison bugs.

Install

pip install dirty-equals Install stable version

Imports

IsInt
```
from dirty_equals import IsInt
```
IsStr
```
from dirty_equals import IsStr
```
IsNow
```
from dirty_equals import IsNow
```
IsListOrTuple
```
from dirty_equals import IsListOrTuple
```
IsUrl
```
from dirty_equals import IsUrl
```

Quickstart

Demonstrates basic usage of dirty-equals for type checking, fuzzy time comparisons, and asserting elements within collections. The `IsNow()` helper provides a flexible way to compare datetimes without needing an exact match, useful in tests.

from datetime import datetime
from dirty_equals import IsInt, IsStr, IsNow, IsListOrTuple

# Basic type checking
assert 123 == IsInt()
assert "hello" == IsStr()

# Fuzzy time comparison (matches if within a reasonable delta)
now_time = datetime.now()
# The library internally compares against datetime.now() at the moment of assertion.
# The assertion will pass if now_time is approximately equal to the current time.
assert now_time == IsNow()

# Asserting content and types within collections
assert [1, "two", 3] == IsListOrTuple(IsInt(), IsStr(), IsInt())

print("Dirty equals assertions successful!")

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