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https://github.com/lycantropos/lz
Functional utilities
https://github.com/lycantropos/lz
currying functional-programming lazy-evaluation
Last synced: 7 days ago
JSON representation
Functional utilities
- Host: GitHub
- URL: https://github.com/lycantropos/lz
- Owner: lycantropos
- License: mit
- Created: 2018-05-04T20:33:42.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2023-02-23T23:36:37.000Z (over 1 year ago)
- Last Synced: 2024-09-08T12:10:07.576Z (2 months ago)
- Topics: currying, functional-programming, lazy-evaluation
- Language: Python
- Homepage: https://lz.readthedocs.io
- Size: 499 KB
- Stars: 6
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
lz
==
[](https://github.com/lycantropos/lz/actions/workflows/ci.yml "Github Actions")
[](https://codecov.io/gh/lycantropos/lz "Codecov")
[](https://lz.readthedocs.io/en/latest "Documentation")
[](https://github.com/lycantropos/lz/blob/master/LICENSE "License")
[](https://badge.fury.io/py/lz "PyPI")
In what follows `python` is an alias for `python3.7` or `pypy3.7`
or any later version (`python3.8`, `pypy3.8` and so on).
Installation
------------
Install the latest `pip` & `setuptools` packages versions
```bash
python -m pip install --upgrade pip setuptools
```
### User
Download and install the latest stable version from `PyPI` repository
```bash
python -m pip install --upgrade lz
```
### Developer
Download the latest version from `GitHub` repository
```bash
git clone https://github.com/lycantropos/lz.git
cd lz
```
Install dependencies
```bash
python -m pip install -r requirements.txt
```
Install
```bash
python setup.py install
```
Usage
-----
`lz` provides a bunch of utilities for working with functions, predicates & iterables such as
1. [function composition](https://en.wikipedia.org/wiki/Function_composition)
```python
>>> from lz.functional import compose
>>> sum_of_first_n_natural_numbers = compose(sum, range)
>>> sum_of_first_n_natural_numbers(10)
45
```
2. [currying](https://en.wikipedia.org/wiki/Currying)
```python
>>> from lz.functional import curry
>>> curried_power = curry(pow)
>>> two_to_power = curried_power(2)
>>> two_to_power(10)
1024
```
3. flipping positional parameters order
```python
>>> from lz.functional import flip
>>> flipped_power = flip(pow)
>>> flipped_power(2, 3)
9
```
4. packing function's arguments
```python
>>> from lz.functional import pack
>>> packed_int = pack(int)
>>> packed_int(['10'])
10
>>> packed_int(['10'], {'base': 2})
2
```
5. left [partial application](https://en.wikipedia.org/wiki/Partial_application)
```python
>>> from lz import left
>>> count_from_zero_to = left.applier(range, 0)
>>> list(count_from_zero_to(10))
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
```
6. right [partial application](https://en.wikipedia.org/wiki/Partial_application)
```python
>>> from lz import right
>>> square = right.applier(pow, 2)
>>> square(10)
100
```
7. [negating](https://en.wikipedia.org/wiki/Negation) predicate
```python
>>> from lz.logical import negate
>>> false_like = negate(bool)
>>> false_like([])
True
>>> false_like([0])
False
```
8. [conjoining](https://en.wikipedia.org/wiki/Logical_conjunction) predicates
```python
>>> from lz.logical import conjoin
>>> is_valid_constant_identifier = conjoin(str.isupper, str.isidentifier)
>>> is_valid_constant_identifier('SECOND_SECTION')
True
>>> is_valid_constant_identifier('2ND_SECTION')
False
```
9. [disjoining](https://en.wikipedia.org/wiki/Logical_disjunction) predicates
```python
>>> from lz.logical import disjoin
>>> alphabetic_or_numeric = disjoin(str.isalpha, str.isnumeric)
>>> alphabetic_or_numeric('Hello')
True
>>> alphabetic_or_numeric('42')
True
>>> alphabetic_or_numeric('Hello42')
False
```
10. [exclusive disjoining](https://en.wikipedia.org/wiki/Exclusive_or) predicates
```python
>>> from lz.logical import exclusive_disjoin
>>> from keyword import iskeyword
>>> valid_object_name = exclusive_disjoin(str.isidentifier, iskeyword)
>>> valid_object_name('valid_object_name')
True
>>> valid_object_name('_')
True
>>> valid_object_name('1')
False
>>> valid_object_name('lambda')
False
```
11. reversing sequences and any string streams
```python
>>> from lz.reversal import reverse
>>> list(reverse(range(10)))
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
>>> import io
>>> list(reverse(io.BytesIO(b'Hello\nWorld!')))
[b'World!', b'Hello\n']
```
12. chunking iterable
```python
>>> from lz.iterating import chopper
>>> to_triplets = chopper(3)
>>> list(map(tuple, to_triplets(range(10))))
[(0, 1, 2), (3, 4, 5), (6, 7, 8), (9,)]
```
13. sliding over iterable
```python
>>> from lz.iterating import slider
>>> slide_pairwise = slider(2)
>>> list(slide_pairwise(range(10)))
[(0, 1), (1, 2), (2, 3), (3, 4), (4, 5), (5, 6), (6, 7), (7, 8), (8, 9)]
```
14. [interleaving](https://en.wikipedia.org/wiki/Interleave_sequence) iterables
```python
>>> from lz.iterating import interleave
>>> list(interleave([range(10), range(10, 20)]))
[0, 10, 1, 11, 2, 12, 3, 13, 4, 14, 5, 15, 6, 16, 7, 17, 8, 18, 9, 19]
```
15. iterable [transposition](https://en.wikipedia.org/wiki/Transpose)
```python
>>> from lz.transposition import transpose
>>> list(map(tuple, transpose(zip(range(10), range(10, 20)))))
[(0, 1, 2, 3, 4, 5, 6, 7, 8, 9), (10, 11, 12, 13, 14, 15, 16, 17, 18, 19)]
```
16. iterable duplication
```python
>>> from lz.replication import duplicate
>>> list(map(tuple, duplicate(range(10))))
[(0, 1, 2, 3, 4, 5, 6, 7, 8, 9), (0, 1, 2, 3, 4, 5, 6, 7, 8, 9)]
```
and [many more](https://lz.readthedocs.io/en/latest).
Development
-----------
### Building docs
Install project in editable mode
```bash
python -m pip install -e .
```
Install dependencies
```bash
python -m pip install -r docs/requirements.txt
```
Build docs
```bash
cd docs
make html
```
### Bumping version
#### Preparation
Install
[bump2version](https://github.com/c4urself/bump2version#installation).
#### Pre-release
Choose which version number category to bump following [semver
specification](http://semver.org/).
Test bumping version
```bash
bump2version --dry-run --verbose $CATEGORY
```
where `$CATEGORY` is the target version number category name, possible
values are `patch`/`minor`/`major`.
Bump version
```bash
bump2version --verbose $CATEGORY
```
This will set version to `major.minor.patch-alpha`.
#### Release
Test bumping version
```bash
bump2version --dry-run --verbose release
```
Bump version
```bash
bump2version --verbose release
```
This will set version to `major.minor.patch`.
### Running tests
Install dependencies
```bash
python -m pip install -r requirements-tests.txt
```
Plain
```bash
pytest
```
Inside `Docker` container:
- with `CPython`
```bash
docker-compose --file docker-compose.cpython.yml up
```
- with `PyPy`
```bash
docker-compose --file docker-compose.pypy.yml up
```
`Bash` script (e.g. can be used in `Git` hooks):
- with `CPython`
```bash
./run-tests.sh
```
or
```bash
./run-tests.sh cpython
```
- with `PyPy`
```bash
./run-tests.sh pypy
```
`PowerShell` script (e.g. can be used in `Git` hooks):
- with `CPython`
```powershell
.\run-tests.ps1
```
or
```powershell
.\run-tests.ps1 cpython
```
- with `PyPy`
```powershell
.\run-tests.ps1 pypy
```