This library implements a number of iterator building blocks inspired by Python 3 itertools module. Each has been recast in a form suitable for C#.
You can either register Itertools class in DI (Dependency Injection)
services.AddItertools();... or instantiate manually.
IItertools itertools = new Itertools();using CSharpItertools;
var itertools = new Itertools();
foreach (char letter in itertools.Cycle("ABCD"))
Console.WriteLine(letter);Output:
A
B
C
D
A
B
... // repeats indefinitely
Make an iterator that aggregates elements from each of the iterables.
using CSharpItertools;
var itertools = new Itertools();
var iterable1 = new[] { 1, 2, 3 };
var iterable2 = new[] { 'A', 'B', 'C', 'D' };
forech (var item in itertools.Zip(iterable1, iterable2))
Console.WriteLine(item);
forech (var item in itertools.ZipLongest(iterable1, iterable2))
Console.WriteLine(item);Output Zip:
(1, A)
(2, B)
(3, C)
Output ZipLongest:
- If the iterables are of uneven length, missing values are filled-in with
null. Iteration continues until the longest iterable is exhausted.
(1, A)
(2, B)
(3, C)
(, D)
Make an iterator that filters elements from iterable returning only those for which the predicate is false.
using CSharpItertools;
var itertools = new Itertools();
var iterable = new[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
foreach (int i in itertools.FilterFalse(x => x % 2 > 0, iterable))
Console.WriteLine(i);Output:
2
4
6
8
Make an iterator that returns selected elements from the iterable.
using CSharpItertools;
var itertools = new Itertools();
var iterable = new[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I' };
foreach (char l in itertools.ISlice(iterable, start: 3, stop: 6))
Console.WriteLine(l);Output:
D
E
F
Make an iterator that filters elements from data returning only those that have a corresponding element in selectors that evaluates to true.
using CSharpItertools;
var itertools = new Itertools();
var iterable = new[] { 'X', 'Y', 'Z', 'W' };
var selectors = new object[] { true, false, true, null };
foreach (char l in itertools.Compress(iterable, selectors))
Console.WriteLine(l);Output:
X
8829
Z
Cartesian product of input iterables.
using CSharpItertools;
var itertools = new Itertools();
var iterable1 = new List<int> { 1, 2, 3 };
var iterable2 = new List<int> { 6, 7 };
foreach (var arr in itertools.Product(iterable1, iterable2))
Console.WriteLine("[{0}, {1}]", arr[0], arr[1]); // Output 1
var iterable3 = new[] { 'X', 'Y', 'Z' };
foreach (var arr in itertools.Product(iterable3, repeat: 2))
Console.WriteLine("[{0}, {1}]", arr[0], arr[1]); // Output 2Output 1:
[1, 6]
[1, 7]
[2, 6]
[2, 7]
[3, 6]
[3, 7]
Output 2:
[X, X]
[X, Y]
[X, Z]
[Y, X]
[Y, Y]
[Y, Z]
[Z, X]
[Z, Y]
[Z, Z]
Return successive r length permutations of elements in the iterable.
using CSharpItertools;
var itertools = new Itertools();
var iterable = "ABCD";
foreach (var arr in itertools.Permutations(iterable, 2))
Console.WriteLine("[{0}, {1}]", arr[0], arr[1]);Output:
[A, B]
[A, C]
[A, D]
[B, A]
[B, C]
[B, D]
[C, A]
[C, B]
[C, D]
[D, A]
[D, B]
[D, C]
Return r length subsequences of elements from the input iterable.
using CSharpItertools;
var itertools = new Itertools();
var iterable = new object[] { 'A', 3, 9, 'Z' };
foreach (object[] arr in itertools.Combinations(iterable, 3))
Console.WriteLine("[{0}, {1}, {2}]", arr[0], arr[1], arr[2]);Output:
[A, 3, 9]
[A, 3, Z]
[A, 9, Z]
[3, 9, Z]