# TypeError: 'NoneType' object is not callable  (at np.random.seed)

- **ID:** `python/numpy-random-seed-none`
- **Domain:** python
- **Category:** type_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Code does `seed = np.random.seed(42)` then calls `seed()`. np.random.seed returns None, not a callable.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **** (98% success)
   ```
   np.random.seed(42)  # call directly, don't assign
   ```
2. **** (95% success)
   ```
   rng = np.random.default_rng(42)  # modern API
   ```

## Dead Ends

- **** — Works once but confusing and easy to break (60% fail)
- **** — Calls None, same error (95% fail)