# AssertionError: expected call not found.
Expected: mock(1, 2, 3)
Actual: mock(1, 2)

- **ID:** `python/unittest-mock-assert_called_with-failure`
- **Domain:** python
- **Category:** runtime_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The mock object was called with different arguments than expected, often due to a bug in the code under test or incorrect test expectations.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.8 | active | — | — |
| 3.9 | active | — | — |
| 3.10 | active | — | — |
| 3.11 | active | — | — |
| 3.12 | active | — | — |

## Workarounds

1. **** (90% success)
   ```
   Debug the actual arguments by printing mock.call_args_list or using `print(mock.mock_calls)`
   ```
2. **** (95% success)
   ```
   Update the test to match the correct arguments, or fix the production code to pass the expected arguments.
   ```

## Dead Ends

- **** — This bypasses the argument validation, allowing incorrect calls to pass undetected. (90% fail)
- **** — The call already happened; timing is not the issue. The arguments are simply wrong. (30% fail)