From d1c5e88acc12445c9d8440dc204dab9af48c842a Mon Sep 17 00:00:00 2001
From: Mark Zhukovsky <mzhukovsky@gmail.com>
Date: Sat, 16 Oct 2021 10:36:07 +0400
Subject: [PATCH 1/2] add index_of, last_index_of, for_each methods  and tests

---
 py_linq/py_linq.py      | 36 ++++++++++++++++++++++++++++++++++++
 tests/test_functions.py | 38 +++++++++++++++++++++++++++++++++-----
 2 files changed, 69 insertions(+), 5 deletions(-)

diff --git a/py_linq/py_linq.py b/py_linq/py_linq.py
index bac46e8..65d5553 100644
--- a/py_linq/py_linq.py
+++ b/py_linq/py_linq.py
@@ -86,6 +86,15 @@ def select(self, func=lambda x: x):
         """
         return SelectEnumerable(Enumerable(iter(self)), func)
 
+    def for_each(self, func=lambda x: x):
+        """
+        Execute a given function per each element
+        :param func: the function to execute
+        :return: None
+        """
+        for x in self:
+            func(x)
+
     def sum(self, func=lambda x: x):
         """
         Returns the sum of af data elements
@@ -141,6 +150,33 @@ def median(self, func=lambda x: x):
             else (float(result[i - 1]) + float(result[i])) / float(2)
         )
 
+    def index_of(self, element):
+        """
+        Returns the index of the first occurrence of a given element.
+
+        :param element: the element for which to retrieve the index
+        :return: Index of given element
+        """
+        for i, e in enumerate(self):
+            if e == element:
+                return i
+
+        return None
+
+    def last_index_of(self, element):
+        """
+        Returns the index of the last occurrence of a given element.
+
+        :param element: the element for which to retrieve the last index
+        :return: Index of last occurence of given element
+        """
+        last_index = self.count() - 1
+        for i, e in enumerate(self.reverse()):
+            if e == element:
+                return last_index - i
+
+        return None
+
     def element_at(self, n):
         """
         Returns element at given index.
diff --git a/tests/test_functions.py b/tests/test_functions.py
index 769e8f0..f9cfc77 100644
--- a/tests/test_functions.py
+++ b/tests/test_functions.py
@@ -1,5 +1,7 @@
+from io import StringIO
 from py_linq.py_linq import SelectEnumerable, WhereEnumerable
 from unittest import TestCase
+from unittest.mock import patch
 from py_linq import Enumerable
 from tests import _empty, _simple, _complex, _locations
 from py_linq.exceptions import (
@@ -94,6 +96,20 @@ def test_select(self):
             .to_list(),
         )
 
+    def test_for_each(self):
+
+        with patch("sys.stdout", new=StringIO()) as fake_out:
+            self.simple.for_each(print)
+            self.assertEqual(fake_out.getvalue(), "1\n2\n3\n")
+
+        with patch("sys.stdout", new=StringIO()) as fake_out:
+            self.complex.for_each(lambda x: print(x["value"]))
+            self.assertEqual(fake_out.getvalue(), "1\n2\n3\n")
+
+        output = []
+        self.complex.for_each(lambda x: output.append(x))
+        self.assertListEqual(output, self.complex.to_list())
+
     def test_min(self):
         self.assertRaises(NoElementsError, self.empty.min)
         self.assertEqual(1, self.simple.min())
@@ -200,6 +216,16 @@ def test_median(self):
         self.assertEqual(median, self.simple.median())
         self.assertEqual(median, self.complex.median(lambda x: x["value"]))
 
+    def test_index_of(self):
+        self.assertEqual(1, self.simple.index_of(2))
+        self.assertEqual(1, self.complex.index_of({"value": 2}))
+
+    def test_last_index_of(self):
+        self.assertEqual(4, self.simple.concat(Enumerable(_simple)).last_index_of(2))
+        self.assertEqual(
+            4, self.complex.concat(Enumerable(_complex)).last_index_of({"value": 2})
+        )
+
     def test_skip(self):
         self.assertListEqual([], Enumerable().skip(2).to_list())
         self.assertListEqual([], Enumerable([1, 2, 3]).skip(3).to_list())
@@ -849,11 +875,13 @@ def test_to_dictionary(self):
         test = Enumerable(["ab", "bc", "cd", "de"]).to_dictionary(lambda t: t[0])
         self.assertDictEqual(test, {"a": "ab", "b": "bc", "c": "cd", "d": "de"})
 
-        test = Enumerable([
-            [0, 1, 2],
-            [3, 4, 5],
-            [6, 7, 8]
-        ]).to_dictionary(lambda t: t[0], lambda t: t[1:])
+        test = Enumerable(
+            [
+                [0, 1, 2],
+                [3, 4, 5],
+                [6, 7, 8],
+            ]
+        ).to_dictionary(lambda t: t[0], lambda t: t[1:])
         self.assertDictEqual(test, {0: [1, 2], 3: [4, 5], 6: [7, 8]})
 
     def test_zip(self):

From 8fcb299af32786ded3f86b487b0f232e09d4c02a Mon Sep 17 00:00:00 2001
From: Mark Zhukovsky <mzhukovsky@gmail.com>
Date: Sat, 16 Oct 2021 10:37:43 +0400
Subject: [PATCH 2/2] add index_of, last_index_of, for_each methods to docs

---
 docs/for-each.md      | 34 ++++++++++++++++++++
 docs/index-of.md      | 33 +++++++++++++++++++
 docs/index.md         | 73 ++++++++++++++++++++++---------------------
 docs/last-index-of.md | 36 +++++++++++++++++++++
 4 files changed, 141 insertions(+), 35 deletions(-)
 create mode 100644 docs/for-each.md
 create mode 100644 docs/index-of.md
 create mode 100644 docs/last-index-of.md

diff --git a/docs/for-each.md b/docs/for-each.md
new file mode 100644
index 0000000..c6de0df
--- /dev/null
+++ b/docs/for-each.md
@@ -0,0 +1,34 @@
+## for_each
+
+`for_each(n)`
+
+Executes a given function per each element in an `Enumerable` collection. Syntactic sugar for a for loop. This is an executing function.
+
+**Parameters**
+
+__func__ : the function, lambda or otherwise, to execute per each element
+
+**Returns**
+
+None
+
+**Example**
+
+<pre><code>
+from py_linq import Enumerable
+
+Enumerable([1 ,2 ,3]).for_each(print)
+# 1
+# 2
+# 3
+
+Enumerable([
+    {'value': 1},
+    {'value': 2},
+    {'value': 3}
+]).for_each(lambda x: print(x['value']))
+# 1
+# 2
+# 3
+
+</code></pre>
\ No newline at end of file
diff --git a/docs/index-of.md b/docs/index-of.md
new file mode 100644
index 0000000..b816a2a
--- /dev/null
+++ b/docs/index-of.md
@@ -0,0 +1,33 @@
+## index_of
+
+`index_of(n)`
+
+Returns the index of a given element in an `Enumerable` collection. If no matching element is found, None is returned. This is an executing function.
+
+**Parameters**
+
+__element__ : the element to search for and return the index of within the collection
+
+**Returns**
+
+The index of the given element, or None.
+
+**Example**
+
+<pre><code>
+from py_linq import Enumerable
+
+Enumerable([
+    {'value': 1},
+    {'value': 2},
+    {'value': 3}
+]).index_of({'value': 2})
+# 1
+
+Enumerable([
+    {'value': 1},
+    {'value': 2},
+    {'value': 3}
+]).index_of({'value': 4})
+# None
+</code></pre>
\ No newline at end of file
diff --git a/docs/index.md b/docs/index.md
index 384f1e0..5056d4d 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -42,38 +42,41 @@ Once you have created an `Enumerable` instance, the LINQ methods will become ava
 11. [intersect](/py-enumerable/intersect)
 12. [except_](/py-enumerable/except)
 13. [to_list](/py-enumerable/to-list)
-14. [count](/py-enumerable/count)
-15. [sum](/py-enumerable/sum)
-16. [min](/py-enumerable/min)
-17. [max](/py-enumerable/max)
-18. [avg](/py-enumerable/avg)
-19. [median](/py-enumerable/median)
-20. [any](/py-enumerable/any)
-21. [element_at](/py-enumerable/element-at)
-22. [element_at_or_default](/py-enumerable/element-at-or-default)
-23. [first](/py-enumerable/first)
-24. [first_or_default](/py-enumerable/first-or-default)
-25. [last](/py-enumerable/last)
-26. [last_or_default](/py-enumerable/last-or-default)
-27. [contains](/py-enumerable/contains)
-28. [group_by](/py-enumerable/group-by)
-29. [distinct](/py-enumerable/distinct)
-30. [group_join](/py-enumerable/group-join)
-31. [union](/py-enumerable/union)
-32. [all](/py-enumerable/all)
-33. [aggregate](/py-enumerable/aggregate)
-34. [append](/py-enumerable/append)
-35. [prepend](/py-enumerable/prepend)
-36. [empty](/py-enumerable/empty)
-37. [range](/py-enumerable/range)
-38. [repeat](/py-enumerable/repeat)
-39. [reverse](/py-enumerable/reverse)
-40. [skip_last](/py-enumerable/skip_last)
-41. [skip_while](/py-enumerable/skip_while)
-42. [take_last](/py-enumerable/take_last)
-43. [take_while](/py-enumerable/take_while)
-44. [zip](/py-enumerable/zip)
-45. [default_if_empty](/py-enumerable/default_if_empty)
-46. [single](/py-enumerable/single)
-47. [single_or_default](/py-enumerable/single-or-default)
-48. [to_dictionary](/py-enumerable/to-dictionary)
\ No newline at end of file
+14. [for_each](/py-enumerable/for-each)
+15. [count](/py-enumerable/count)
+16. [sum](/py-enumerable/sum)
+17. [min](/py-enumerable/min)
+18. [max](/py-enumerable/max)
+19. [avg](/py-enumerable/avg)
+20. [median](/py-enumerable/median)
+21. [any](/py-enumerable/any)
+22. [index_of](/py-enumerable/index-of)
+23. [last_index_of](/py-enumerable/last-index-of)
+24. [element_at](/py-enumerable/element-at)
+25. [element_at_or_default](/py-enumerable/element-at-or-default)
+26. [first](/py-enumerable/first)
+27. [first_or_default](/py-enumerable/first-or-default)
+28. [last](/py-enumerable/last)
+29. [last_or_default](/py-enumerable/last-or-default)
+30. [contains](/py-enumerable/contains)
+31. [group_by](/py-enumerable/group-by)
+32. [distinct](/py-enumerable/distinct)
+33. [group_join](/py-enumerable/group-join)
+34. [union](/py-enumerable/union)
+35. [all](/py-enumerable/all)
+36. [aggregate](/py-enumerable/aggregate)
+37. [append](/py-enumerable/append)
+38. [prepend](/py-enumerable/prepend)
+39. [empty](/py-enumerable/empty)
+40. [range](/py-enumerable/range)
+40. [repeat](/py-enumerable/repeat)
+41. [reverse](/py-enumerable/reverse)
+42. [skip_last](/py-enumerable/skip_last)
+43. [skip_while](/py-enumerable/skip_while)
+44. [take_last](/py-enumerable/take_last)
+45. [take_while](/py-enumerable/take_while)
+46. [zip](/py-enumerable/zip)
+47. [default_if_empty](/py-enumerable/default_if_empty)
+48. [single](/py-enumerable/single)
+49. [single_or_default](/py-enumerable/single-or-default)
+50. [to_dictionary](/py-enumerable/to-dictionary)
\ No newline at end of file
diff --git a/docs/last-index-of.md b/docs/last-index-of.md
new file mode 100644
index 0000000..bb0edb2
--- /dev/null
+++ b/docs/last-index-of.md
@@ -0,0 +1,36 @@
+## last_index_of
+
+`last_index_of(n)`
+
+Returns the index of the last occurrence of a given element in an `Enumerable` collection. If no matching element is found, None is returned. This is an executing function.
+
+**Parameters**
+
+__element__ : the element to search for and return the last index of within the collection
+
+**Returns**
+
+The last index of the given element, or None.
+
+**Example**
+
+<pre><code>
+from py_linq import Enumerable
+
+Enumerable([
+    {'value': 1},
+    {'value': 2},
+    {'value': 3},
+    {'value': 1},
+    {'value': 2},
+    {'value': 3}
+]).last_index_of({'value': 2})
+# 4
+
+Enumerable([
+    {'value': 1},
+    {'value': 2},
+    {'value': 3}
+]).last_index_of({'value': 4})
+# None
+</code></pre>
\ No newline at end of file