pylinq

• pylinq
  • Features
  • Dependencies
  • Installation
  • Usage
  • Supported types
  • Supported methods
  • Non Supported methods

Features

• LINQ implementation in Python3
• Supports almost all LINQ methods in .NET
• All methods and types have complete type hints
• Some methods supports overloads

Dependencies

• Python: >= 3.11
• Package: Nothing

Installation

Execute shell commands below at your python workspace

git clone git@github.com:Funny-Silkie/pylinq.git
mv pylinq tmp
cp -r tmp/src/pylinq .
rm -rf tmp

Usage

1. import pylinq package
2. LinqSequence[T] is LINQ object (think as IEnumerable<T> in .NET)
3. from_iterable() method creates a new LinqSequence[T] instance from an Iterable[T] instance
4. Method chain can be described from a instance of LinqSequence[T]

from pylinq import LinqSequence

sequence: LinqSequence[int] = LinqSequence.from_iterable(range(10))\
    .where(lambda x: x % 2 == 0)\
    .select(lambda x: x * 10)
for current in sequence:
    print(current)

Output

0
20
40
60
80

from_generator() method creates a new LinqSequence[T] instance from a generator function and its arguments. The instance generated from from_generator() supports many times iterations.

from typing import Generator
from pylinq import LinqSequence


def generator(stop: str) -> Generator[str, None, None]:
    yield "A"
    yield "B"
    yield "C"
    yield stop


sequence: LinqSequence[str] = LinqSequence.from_generator(generator, "Finished")
for current in sequence:
    print(current)
for current in sequence:
    print(current)

Output

A
B
C
Finished
A
B
C
Finished

Supported types

All types described below can be imported from pylinq module.

Type in pylinq	Corresponding .NET Type
LinqSequence[T]	IEnumerable<T>
OrderedLinqSequence[T]	IOrderedEnumerable<T>
Grouping[TKey, T]	IGrouping<TKey, TElement>
Lookup[TKey, TValue]	ILookup<TKey, TElement>

Supported methods

• Almost all .NET LINQ methods are supported
• Except method is implemented as excepted in this library because of collision with except keyword
• some methods have overloads and several return types

Category	Method in pylinq	Return	Corresponding .NET method
Creating	from_iterable	LinqSequence[T]	-
Creating	from_dict	LinqSequence[tuple[TKey, TValue]]	-
Creating	from_generator	LinqSequence[T]	-
Creating	empty	LinqSequence[T]	Empty
Creating	range	LinqSequence[int]	Range
Creating	repeat	LinqSequence[T]	Repeat
Creating	default_if_empty	LinqSequence[T]	DefaultIfEmpty
Concatenation	concat	LinqSequence[T]	Concat
Concatenation	append	LinqSequence[T]	Append
Concatenation	prepend	LinqSequence[T]	Prepend
joining	join	LinqSequence[TResult]	Join
joining	group_join	LinqSequence[TResult]	GroupJoin
Comparing Sequence	sequence_equal	bool	SequenceEqual
Quantifier Operation	any	bool	Any
Quantifier Operation	all	bool	All
Quantifier Operation	contains	bool	Contains
Get Element	element_at	T	ElementAt
Get Element	element_at_or_default	T	ElementAtOrDefault
Get Element	first	T	First
Get Element	first_or_default	T	FirstOrDefault
Get Element	last	T	Last
Get Element	last_or_default	T	LastOrDefault
Get Element	single	T	Single
Get Element	single_or_default	T	SingleOrDefault
Filtering	where	LinqSequence[T]	Where
Filtering	where	LinqSequence[TResult]	OfType
Grouping	to_look_up	Lookup[TKey, TValue]	ToLookup
Grouping	group_by	LinqSequence[Grouping[TKey, T]] LinqSequence[Grouping[TKey, T2]] LinqSequence[TResult]	GroupBy
Ordering	order	OrderedLinqSequence[T]	Order
Ordering	order_by	OrderedLinqSequence[T]	OrderBy
Ordering	order_descending	OrderedLinqSequence[T]	OrderDescending
Ordering	order_by_descending	OrderedLinqSequence[T]	OrderByDescending
Ordering	then_by	OrderedLinqSequence[T]	ThenBy
Ordering	then_by_descending	OrderedLinqSequence[T]	ThenByDescending
Ordering	reverse	LinqSequence[T]	Reverse
Set Operation	distinct	LinqSequence[T]	Distinct
Set Operation	distinct_by	LinqSequence[T]	DistinctBy
Set Operation	union	LinqSequence[T]	Union
Set Operation	union_by	LinqSequence[T]	UnionBy
Set Operation	excepted	LinqSequence[T]	Except
Set Operation	excepted_by	LinqSequence[T]	ExceptBy
Set Operation	intersect	LinqSequence[T]	Intersect
Set Operation	intersect_by	LinqSequence[T]	IntersectBy
Partitioning	skip	LinqSequence[T]	Skip
Partitioning	skip_last	LinqSequence[T]	SkipLast
Partitioning	skip_while	LinqSequence[T]	SkipWhile
Partitioning	take	LinqSequence[T]	Take
Partitioning	take_last	LinqSequence[T]	TakeLast
Partitioning	take_while	LinqSequence[T]	TakeWhile
Partitioning	chunk	LinqSequence[list[T]]	Chunk
Projection	select	LinqSequence[TResult]	Select
Projection	select_many	LinqSequence[T2] LinqSequence[TResult]	SelectMany
Projection	zip	LinqSequence[tuple[T1, T2]] LinqSequence[TResult]	Zip
Conversion	to_list	list[T]	ToList
Conversion	to_dict	dict[TKey, T] dict[TKey, TValue]	ToDictionary
Conversion	to_set	set[T]	ToHashSet
Statistics	count	int	Count LongCount
Statistics	max_by	T	MaxBy
Statistics	min_by	T	MinBy
Statistics	sum	float	Sum
Statistics	average	float	Average
Statistics	aggregate	TAccumulate TResult	Aggregate

Non Supported methods

• Max, Min: Difficult to implement these methods only specific T type
• Cast: Python doesn't have type casting