From 75ccc39b967e1e3900a48951344b4fb178f30864 Mon Sep 17 00:00:00 2001
From: Isabelle Viktoria Maciohsek <maciv@hotmail.gr>
Date: Sat, 14 Mar 2020 11:33:17 +0200
Subject: [PATCH 1/4] Add for_each and for_each_right

---
 for_each.md       | 18 ++++++++++++++++++
 for_each_right.md | 18 ++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 for_each.md
 create mode 100644 for_each_right.md

diff --git a/for_each.md b/for_each.md
new file mode 100644
index 000000000..0e72dc6ae
--- /dev/null
+++ b/for_each.md
@@ -0,0 +1,18 @@
+---
+title: for_each
+tags: list,beginner
+---
+
+Executes the provided function once for each list element.
+
+Use a `for` loop to execute `fn` for each element in `itr`.
+
+```py
+def for_each(itr, fn):
+  for el in itr:
+    fn(el)
+```
+
+```py
+for_each([1, 2, 3], print)  # 1 2 3
+```
diff --git a/for_each_right.md b/for_each_right.md
new file mode 100644
index 000000000..c95f7497b
--- /dev/null
+++ b/for_each_right.md
@@ -0,0 +1,18 @@
+---
+title: for_each_right
+tags: list,beginner
+---
+
+Executes the provided function once for each list element, starting from the list's last element.
+
+Use a `for` loop in combination with slice notation to execute `fn` for each element in `itr`, starting from the last one.
+
+```py
+def for_each_right(itr, fn):
+  for el in itr[::-1]:
+    fn(el)
+```
+
+```py
+for_each_right([1, 2, 3], print)  # 3 2 1
+```

From b047b8f546273b0dff5ef585ec00398b3450c9de Mon Sep 17 00:00:00 2001
From: Isabelle Viktoria Maciohsek <maciv@hotmail.gr>
Date: Sat, 14 Mar 2020 11:33:48 +0200
Subject: [PATCH 2/4] Add frequencies

---
 frequencies.md | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 frequencies.md

diff --git a/frequencies.md b/frequencies.md
new file mode 100644
index 000000000..f260e7353
--- /dev/null
+++ b/frequencies.md
@@ -0,0 +1,22 @@
+---
+title: frequencies
+tags: list,intermediate
+---
+
+Returns a dictionary with the unique values of a list as keys and their frequencies as the values.
+
+Use a `for` loop to populate a dictionary, `f`, with the unique values in `lst` as keys, adding to existing keys every time the same value is encountered.
+
+```py
+from functools import reduce
+
+def frequencies(lst):
+  f = {}
+  for x in lst:
+    f[x] = f[x] + 1 if x in f else 1
+  return f
+```
+
+```py
+frequencies(['a', 'b', 'a', 'c', 'a', 'a', 'b']) # { 'a': 4, 'b': 2, 'c': 1 }
+```

From 53c0329a89ebda2b960da2b2d9ed956434a9f850 Mon Sep 17 00:00:00 2001
From: Isabelle Viktoria Maciohsek <maciv@hotmail.gr>
Date: Sat, 14 Mar 2020 11:34:52 +0200
Subject: [PATCH 3/4] Add have_same_contents, includes_all and includes_any

---
 have_same_contents.md | 22 ++++++++++++++++++++++
 includes_all.md       | 21 +++++++++++++++++++++
 includes_any.md       | 21 +++++++++++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 have_same_contents.md
 create mode 100644 includes_all.md
 create mode 100644 includes_any.md

diff --git a/have_same_contents.md b/have_same_contents.md
new file mode 100644
index 000000000..d29afa78e
--- /dev/null
+++ b/have_same_contents.md
@@ -0,0 +1,22 @@
+---
+title: have_same_contents
+tags: list,intermediate
+---
+
+Returns `True` if two lists contain the same elements regardless of order, `False` otherwise.
+
+Use `set()` on combination of both lists to find the unique values.
+Iterate over them with a `for` loop comparing the `count()` of each unique value in each array.
+Return `False` if the counts do not match for any element, `True` otherwise.
+
+```py
+def have_same_contents(a, b):
+  for v in set(a + b):
+    if a.count(v) != b.count(v):
+      return False
+  return True
+```
+
+```py
+have_same_contents([1, 2, 4], [2, 4, 1]) # True
+```
diff --git a/includes_all.md b/includes_all.md
new file mode 100644
index 000000000..d2a3eab41
--- /dev/null
+++ b/includes_all.md
@@ -0,0 +1,21 @@
+---
+title: includes_all
+tags: utility,intermediate
+---
+
+Returns `True` if all the elements in `values` are included in `lst`, `False` otherwise.
+
+Check if every value in `values` is contained in `lst` using a `for` loop, returning `False` if any one value is not found, `True` otherwise.
+
+```py
+def includes_all(lst, values):
+  for v in values:
+    if v not in lst:
+      return False
+  return True
+```
+
+```py
+includes_all([1, 2, 3, 4], [1, 4]) # True
+includes_all([1, 2, 3, 4], [1, 5]) # False
+```
diff --git a/includes_any.md b/includes_any.md
new file mode 100644
index 000000000..12c511973
--- /dev/null
+++ b/includes_any.md
@@ -0,0 +1,21 @@
+---
+title: includes_any
+tags: list,intermediate
+---
+
+Returns `True` if any the elements in `values` are included in `lst`, `False` otherwise.
+
+Check if any value in `values` is contained in `lst` using a `for` loop, returning `True` if any one value is found, `False` otherwise.
+
+```py
+def includes_any(lst, values):
+  for v in values:
+    if v in lst:
+      return True
+  return False
+```
+
+```py
+includes_any([1, 2, 3, 4], [2, 9]) # True
+includes_any([1, 2, 3, 4], [8, 9]) # False
+```

From 223785a49ff4066f31897c199d41e9177ed10922 Mon Sep 17 00:00:00 2001
From: Isabelle Viktoria Maciohsek <maciv@hotmail.gr>
Date: Sat, 14 Mar 2020 11:40:50 +0200
Subject: [PATCH 4/4] Apply suggestions from code review

Co-Authored-By: Angelos Chalaris <chalarangelo@gmail.com>
---
 for_each.md           | 2 +-
 for_each_right.md     | 2 +-
 have_same_contents.md | 4 ++--
 includes_any.md       | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/for_each.md b/for_each.md
index 0e72dc6ae..d4b36999d 100644
--- a/for_each.md
+++ b/for_each.md
@@ -14,5 +14,5 @@ def for_each(itr, fn):
 ```
 
 ```py
-for_each([1, 2, 3], print)  # 1 2 3
+for_each([1, 2, 3], print) # 1 2 3
 ```
diff --git a/for_each_right.md b/for_each_right.md
index c95f7497b..64bb2e075 100644
--- a/for_each_right.md
+++ b/for_each_right.md
@@ -14,5 +14,5 @@ def for_each_right(itr, fn):
 ```
 
 ```py
-for_each_right([1, 2, 3], print)  # 3 2 1
+for_each_right([1, 2, 3], print) # 3 2 1
 ```
diff --git a/have_same_contents.md b/have_same_contents.md
index d29afa78e..15f8baa57 100644
--- a/have_same_contents.md
+++ b/have_same_contents.md
@@ -5,8 +5,8 @@ tags: list,intermediate
 
 Returns `True` if two lists contain the same elements regardless of order, `False` otherwise.
 
-Use `set()` on combination of both lists to find the unique values.
-Iterate over them with a `for` loop comparing the `count()` of each unique value in each array.
+Use `set()` on the combination of both lists to find the unique values.
+Iterate over them with a `for` loop comparing the `count()` of each unique value in each list.
 Return `False` if the counts do not match for any element, `True` otherwise.
 
 ```py
diff --git a/includes_any.md b/includes_any.md
index 12c511973..459953b11 100644
--- a/includes_any.md
+++ b/includes_any.md
@@ -3,7 +3,7 @@ title: includes_any
 tags: list,intermediate
 ---
 
-Returns `True` if any the elements in `values` are included in `lst`, `False` otherwise.
+Returns `True` if any element in `values` is included in `lst`, `False` otherwise.
 
 Check if any value in `values` is contained in `lst` using a `for` loop, returning `True` if any one value is found, `False` otherwise.