strictly-typed-pandas

================================================================ Strictly Typed Pandas: static type checking of pandas DataFrames

I love Pandas! But in production code I’m always a bit wary when I see:

.. code-block:: python

import pandas as pd

def foo(df: pd.DataFrame) -> pd.DataFrame:
    # do stuff
    return df

Because… How do I know which columns are supposed to be in df?

Using strictly_typed_pandas, we can be more explicit about what these data should look like.

.. code-block:: python

from strictly_typed_pandas import DataSet

class Schema:
    id: int
    name: str

def foo(df: DataSet[Schema]) -> DataSet[Schema]:
    # do stuff
    return df

Where DataSet: * is a subclass of pd.DataFrame and hence has the same functionality as DataFrame. * validates whether the data adheres to the provided schema upon its initialization. * is immutable, so its schema cannot be changed using inplace modifications.

The DataSet[Schema] annotations are compatible with: * mypy for type checking during linting-time (i.e. while you write your code). * typeguard (<v3.0) for type checking during run-time (i.e. while you run your unit tests).

To get the most out of strictly_typed_pandas, be sure to: * set up mypy in your IDE. * run your unit tests with pytest --stp-typeguard-packages=foo.bar (where foo.bar is your package name).

Installation

.. code-block:: bash

pip install strictly-typed-pandas

Documentation

For example notebooks and API documentation, please see our ReadTheDocs <https://strictly-typed-pandas.readthedocs.io/>_.

FAQ

| Do you know of something similar for pyspark? | Yes! Check out our package typedspark <https://github.com/kaiko-ai/typedspark/>_. | | Why use Python if you want static typing? | There are just so many good packages for data science in Python. Rather than sacrificing all of that by moving to a different language, I'd like to make the Pythonverse a little bit better. | | I found a bug! What should I do? | Great! Contact me and I'll look into it. | | I have a great idea to improve strictly_typed_pandas! How can we make this work? | Awesome, drop me a line!