Pandera

Bugfix Release

This release contains two bugfixes:

- coerce nullable str column handles all na (366)
- non-required columns that are not in dataframe are not coerced (368)

🎉🎉🎉 Thanks to jeffzi, ktroutman, m1so for your contributions! 🎉🎉🎉

Enhancements

- Improve memory efficiency of validation process (360)
- Add column order validation (352)
- Implement data synthesis strategies using [hypothesis](https://hypothesis.readthedocs.io/en/latest/) (#344)
- Add support for aliases in `SchemaModel` (329)
- Add support for optional name validation of single-index (326)
- Move columns to multiindex: add `reset_index`, `set_index` method to `DataFrameSchema` (319)
- Add support for Python 3.9 (307)

Bugfixes

- typing.DataFrame should expect annotation input (318)

Deprecations

- `SchemaErrors.schema_errors` has been changed to `failure_cases`, and the `schema_errors` attribute now contains a list of dicts containing schema errors and reason codes. This is a breaking change, but is a minor part of the API and is fairly straightforward to fix (360).

Documentation Improvements

- Add required columns documentation for schema models (362)
- Fix docs: schema examples (347)
- Add documentation for dataframeschema transformations (333)
- Fix deprecated SchemaErrorReport references in docs (310)
- Fix SchemaModel dtype example (309)

Repo Improvements

- Update logo 69c6e56a0961bb0a9f37947f040209fd71dd3826
- Add `flynt` to pre-commit hooks (325)
- Use generic zenodo link for citation information c4f4fe780729ee82444709910b5f2a7f206d3c81

pandera relied on the packaging package to get version information to determine pandas legacy status. This was an implicit sub-dependency of one of pandera's dependencies, which was apparently dropped and led to a bug: 335. This bugfix version explicitly adds packaging.

Enhancements

- Implement class-based API for pydantic-style schema definitions 786b5041350e21775e5d95603b3460837e67cbc8. Big thanks to jeffzi 🎉
- Add `inplace=False` argument to `schema.validate` method to prevent mutation of original dataframe 586ebf3ba550f204f7433247e8628507bb35597c.
- Make pandera optional extensions `[hypothesis]`, `[io]`, `[all]` available c4716a0ff1f054b8ab0ef5de68e40b5f9de3472d. Thanks amitripshtos and jeffzi 🎉
- Add support for complex number data types 50e86e441322c25186e5b3d7bcb267eacac1be1c thanks ferhah 🎉
- Add support for numpy scalar types a519db5b398db943e3725e96426f2d5f886267f4
- Add `check_io` decorator for check inputs and outputs of a function 913cbd77345035d9c14d34c02efe9f899aa08e79
- Throw SchemaError with column name instead of ValueError for nulls in int series f7b03e35a9cebe21a067d585bb1e1c95c02439df thanks TheCleric 🎉

Bugfixes

- Bugfix io.to_script and to_yaml: Ignoring serializing Checks with lambda functions da9c3a52ef22b6273d8edcb48045b8fe9eff9967 thanks ferhah 🎉

Deprecations

- Drop support for Python 3.5 91e21a2bf769096e80cf7c08c1311ee06aadebb6
- Deprecate `transformers` argument in `DataFrameSchema` init 89c3c9162df8cd3ea0eba4b25e5f6700108c3532

Documentation Improvements

- Fix incorrect docstring 47bc7b851bdbd1e6b11d2064e7ee06ccd4b39d94, thanks areeh 🎉

Repo Improvements

- Update contributing guide 3c4589d00681948b404d1dbe594470b96a96bdf6
- Add funding page be23c4e3d9c5187b7f30a0cecd55751a423dd945

Enhancements

- improve failure case reporting more intuitive 232
- rename internal decorator for setting check statistics 235 thanks Aditya1001001
- from_yaml supports all column properties 240 thanks d33bs
- support for nullable integer string aliases and dtypes 244
- add `check_output` to the `CheckResult` namedtuple 251
- built-in python scalar types are supported: int, float, str, bool 263
- Use Check.name in Check.__repr__ 265 thanks JacobHayes
- add comparison operator aliases to built-in checks 269
- add support for `SeriesSchema` index specification 270

Bugfixes

- io serialization can handle Index.name = None 248
- pandas_dtype can be correctly set in `Column` object 256
- fix `check_input` decorator when df passed in kwargs 257 thanks vshulyak

Documentation Improvements

- Fixed broken link to pandas dtypes 264 thanks ericmjl

New Features

- `DataFrameSchema` provides `rename_columns` method 226 baskervilski
- Failure case reporting is more intuitive as a tidy dataframe 232

Bugfixes

- yaml schema files support null index 225 baskervilski
- add details to error reporting in type coercion 193 c3-Anthony-Truchet
- fix column coerce warning in `check_input/output` decorators 228
- renamed internal decorator for check statistics 233 Aditya1001001