[Python] pandera.errors.BackendNotFoundError with Pandas Dataframe

pandera: 0.18.3
pandas: 2.2.2
python: 3.9/3.11


Hi,

I am unable to setup the pandera for pandas dataframe as it complains:

File "/anaconda/envs/data_quality_env/lib/python3.9/site-packages/pandera/api/base/schema.py",
line 96, in get_backend
raise BackendNotFoundError(
pandera.errors.BackendNotFoundError: Backend not found for backend, class: (<class 'data_validation.schemas.case.CaseSchema'>,
<class 'pandas.core.frame.DataFrame'>). Looked up the following base
classes: (<class 'pandas.core.frame.DataFrame'>, <class 'pandas.core.generic.NDFrame'>, <class 'pandas.core.base.PandasObject'>, <class 'pandas.core.accessor.DirNamesMixin'>, <class 'pandas.core.indexing.IndexingMixin'>, <class 'pandas.core.arraylike.OpsMixin'>, <class 'object'>)


My folder structure is:

project/
data_validation/
schema/
case.py
validation/
validations.py
pipeline.py


case.py:

import pandas as pd
import pandera as pa

class CaseSchema(pa.DataFrameSchema):
case_id = pa.Column(pa.Int)


validations.py

import pandas as pd
from data_validation.schemas.case import CaseSchema

def validate_case_data(df: pd.DataFrame) -> pd.DataFrame:
"""Validate a DataFrame against the PersonSchema."""
schema = CaseSchema()
return schema.validate(df)


pipeline.py

import pandas as pd
from data_validation.validation.validations import validate_case_data

def validate_df(df: pd.DataFrame) -> pd.DataFrame:
"""Process data, validating it against the PersonSchema."""
validated_df = validate_case_data(df)
return validated_df

df = pd.DataFrame({
"case_id": [1, 2, 3]
})

processed_df = validate_df(df)

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