pyfuncol 1.2

Functional collections extension functions for Python

pyfuncol

• pyfuncol
  • Installation
  • Usage
    • API
  • Documentation
  • Compatibility
  • Contributing
  • License

A Python functional collections library. It extends collections built-in types with useful methods to write functional Python code. It uses Forbidden Fruit under the hood.

Installation

pip install pyfuncol

Usage

To use the methods, you just need to import pyfuncol. Some examples:

import pyfuncol

[1, 2, 3, 4].map(lambda x: x * 2).filter(lambda x: x > 4)
# [6, 8]

[1, 2, 3, 4].fold_left(0, lambda acc, n: acc + n)
# 10

{1, 2, 3, 4}.map(lambda x: x * 2).filter_not(lambda x: x <= 4)
# {6, 8}

["abc", "def", "e"].group_by(lambda s: len(s))
# {3: ["abc", "def"], 1: ["e"]}

{"a": 1, "b": 2, "c": 3}.flat_map(lambda kv: {kv[0]: kv[1] ** 2})
# {"a": 1, "b": 4, "c": 9}

pyfuncol provides parallel operations (for now par_map, par_flat_map, par_filter and par_filter_not):

[1, 2, 3, 4].par_map(lambda x: x * 2).par_filter(lambda x: x > 4)
# [6, 8]

{1, 2, 3, 4}.par_map(lambda x: x * 2).par_filter_not(lambda x: x <= 4)
# {6, 8}

{"a": 1, "b": 2, "c": 3}.par_flat_map(lambda kv: {kv[0]: kv[1] ** 2})
# {"a": 1, "b": 4, "c": 9}

pyfuncol provides operations leveraging memoization to improve performance (for now pure_map, pure_flat_map, pure_filter and pure_filter_not). These versions work only for pure functions (i.e., all calls to the same args return the same value) on hashable inputs:

[1, 2, 3, 4].pure_map(lambda x: x * 2).pure_filter(lambda x: x > 4)
# [6, 8]

{1, 2, 3, 4}.pure_map(lambda x: x * 2).pure_filter_not(lambda x: x <= 4)
# {6, 8}

{"a": 1, "b": 2, "c": 3}.pure_flat_map(lambda kv: {kv[0]: kv[1] ** 2})
# {"a": 1, "b": 4, "c": 9}

API

For lists, please refer to the docs.

For dictionaries, please refer to the docs.

For sets and frozensets, please refer to the docs.

For more details, please have a look at the API reference.

We support all subclasses with default constructors (OrderedDict, for example).

Documentation

See https://pyfuncol.readthedocs.io/.

Compatibility

Since it depends on Forbidden Fruit, it only works on CPython.

Contributing

See the contributing guide for detailed instructions on how to get started with the project.

License

pyfuncol is licensed under the MIT license.