Pandas validation results in doubled log messages

[fredsonnenwald]

If I modify the README.md example to add a logger to log the validation error then that error is printed twice, e.g.,

$ python teset.py 
2025-06-25 14:06:09,963 - simple_example - ERROR - Validation failed!
ERROR:simple_example:Validation failed!

That output was generated by

import logging
import pandas as pd
from pydantic import BaseModel
from pydantic.types import StrictInt
from pandantic import Pandantic

# create logger - https://docs.python.org/3/howto/logging.html#logging-advanced-tutorial
logger = logging.getLogger('simple_example')
logger.setLevel(logging.DEBUG)
ch = logging.StreamHandler()
ch.setLevel(logging.DEBUG)
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
ch.setFormatter(formatter)
logger.addHandler(ch)

# Define your schema using Pydantic BaseModel
class DataFrameSchema(BaseModel):
    """Example schema for testing."""
    example_str: str
    example_int: StrictInt

# Create a validator instance
validator = Pandantic(schema=DataFrameSchema)

# Example DataFrame with some invalid data
df_invalid = pd.DataFrame(
    data={
        "example_str": ["foo", "bar", 1],  # Last value is invalid (int instead of str)
        "example_int": ["1", 2, 3.0],      # First and last values are invalid (str and float)
    }
)

# Validate with error raising
try:
    validator.validate(dataframe=df_invalid, errors="raise")
except ValueError:
    logger.error("Validation failed!")

I think the double error message comes from the Pandas validator in

pandantic/src/pandantic/validators/pandas.py

Line 63 in 59732ed

logging.debug("Amount of available cores: %s", os.cpu_count())

and could be mitigated by instead using logging the same way the Pandas plugin works with

pandantic/src/pandantic/plugins/pandas.py

Line 23 in 59732ed

logger = logging.getLogger(__name__)

and calling logger.debug instead of logging.debug, etc.