types-linq 0.0.1

LINQ with full typing support (WIP).

types-linq

This is an attempt to implement linq methods seen in .NET (link). Currently WIP.

To run the test cases, install pytest, and then invoke it under the current directory:

$ pytest

To install it on the computer, do

$ pip install .
# or
$ python setup.py install

The usage is simple if you know about the interfaces in .NET as this library provides almost the exact methods:

from dataclasses import dataclass
from types_linq import Enumerable as en

@dataclass
class PetOwner:
    name: str
    pets: List[str]

pet_owners = [
    PetOwner(name='Higa', pets=['Scruffy', 'Sam']),
    PetOwner(name='Ashkenazi', pets=['Walker', 'Sugar']),
    PetOwner(name='Price', pets=['Scratches', 'Diesel']),
    PetOwner(name='Hines', pets=['Dusty']),
]

query = en(pet_owners)                                             \
    .select_many(
        lambda pet_owner: pet_owner.pets,
        lambda pet_owner, pet_name: (pet_owner, pet_name),
    )                                                              \
    .where(lambda owner_and_pet: owner_and_pet[1].startswith('S')) \
    .select(lambda owner_and_pet: {
        'owner': owner_and_pet[0].name, 'pet': owner_and_pet[1],
        }
    )

for obj in query:
    print(obj)

# output:
# {'owner': 'Higa', 'pet': 'Scruffy'}
# {'owner': 'Higa', 'pet': 'Sam'}
# {'owner': 'Ashkenazi', 'pet': 'Sugar'}
# {'owner': 'Price', 'pet': 'Scratches'}

This example is taken from the .NET doc.