# pydantic_core._pydantic_core.ValidationError: 1 validation error for Settings
debug
  Input should be a valid boolean, unable to interpret input [type=bool_parsing, input_value='yes', input_type=str]

- **ID:** `python/pydantic-validation-error-bool-parsing`
- **Domain:** python
- **Category:** type_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Pydantic v2 only accepts a limited set of boolean-like strings ('true','false','1','0','yes','no','on','off' are case-sensitive to specific forms). 'yes' is not accepted by default.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 2.x | active | — | — |

## Workarounds

1. **** (93% success)
   ```
   from pydantic import BaseModel, field_validator

class Settings(BaseModel):
    debug: bool

    @field_validator('debug', mode='before')
    @classmethod
    def parse_bool(cls, v):
        if isinstance(v, str):
            return v.lower() in ('yes','true','1','on')
        return v
   ```
2. **** (90% success)
   ```
   data['debug'] = str(data['debug']).lower() in ('true','1','yes')
   ```

## Dead Ends

- **** — bool('yes') returns True but bool('false') also returns True because any non-empty string is truthy. (95% fail)
- **** — int('yes') raises ValueError immediately. (99% fail)