# AttributeError: 'Flask' object has no attribute 'run'

- **ID:** `python/flask-attributeerror-flask-object-has-no-attribute-run`
- **Domain:** python
- **Category:** runtime_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The Flask app object was not created correctly, possibly due to a naming conflict or incorrect instantiation.

## Version Compatibility

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

## Workarounds

1. **Instantiate Flask correctly.** (95% success)
   ```
   from flask import Flask
app = Flask(__name__)
app.run()
   ```
2. **Check for variable name conflicts.** (90% success)
   ```
   # Ensure 'app' is not used elsewhere
app = Flask(__name__)
# Avoid: app = some_other_object
   ```

## Dead Ends

- **Using 'app = Flask' instead of 'app = Flask(__name__)'.** — Flask is a class; without instantiation, 'app' is the class itself, not an instance. (90% fail)
- **Overwriting the app variable with another object.** — If you assign a different object to 'app', it loses the Flask methods. (70% fail)