Merge pull request #3027 from enkidevs/iterators

Iterators

CHANGELOG.md

@@ -62,6 +62,7 @@ Types of change:
 ### Changed
 - [Html - Link Relative Paths - Change part of PQ as it wasn't worder properly](https://github.com/enkidevs/curriculum/pull/2985)
 - [Python - Format Text Paragraphs With Textwrap - Make the fill method more clear](https://github.com/enkidevs/curriculum/pull/2981)
+- [Python - Iterators - Move single-line commands to a single line, update indentation in codeblocks from 4 to 2 spaces](https://github.com/enkidevs/curriculum/pull/3027)
 
 ## January 4th 2022
 

python/functional-programming/iterators/the-iteration-protocol.md

@@ -34,22 +34,22 @@ Iterators are always implemented as classes. Let's examine an iterator's code fo
 
 ```python
 class Counter(object):
-    def __init__(self, start, finish):
-        self.current = start
-        self.finish = finish
-
-    def __iter__(self):
-        return self
-
-    def __next__(self):
-        if self.current > self.finish:
-            raise StopIteration
-        else:
-            self.current += 1
-            return self.current - 1
+  def __init__(self, start, finish):
+    self.current = start
+    self.finish = finish
+
+  def __iter__(self):
+    return self
+
+  def __next__(self):
+    if self.current > self.finish:
+      raise StopIteration
+    else:
+      self.current += 1
+      return self.current - 1
 ```
 
-We're already familiar with the `iter` and `next` methods. The `init` method is what is called when the iterator is first created, however, it is not a constructor since, the object is already created when the code within `init` is executed. Instead, this is referred to as an initializer.
+We're already familiar with the `iter` and `next` methods. The `init` method is what is called when the iterator is first created. However, it is not a constructor since the object is already created when the code within `init` is executed. Instead, this is referred to as an initializer.
 
 In this `Counter` example, we can see that `init` takes the values defined by the creator of the iterator (the start and finish values) and keeps track of them. The `next` method checks to see if the iterator has gone beyond the defined `finish` value, and if not, increases the current value and returns the value before that. If the value has exceeded the `finish` value, a StopIteration exception is raised. Simple!
 

python/functional-programming/iterators/the-itertools-module-ii.md

@@ -36,9 +36,7 @@ import itertools;
 letters = ['a', 'b', 'c', 'd']
 numbers = [1, 2, 3, 4]
 
-print(
-  list(
-    itertools.chain(letters, numbers)))
+print(list(itertools.chain(letters, numbers)))
 
 # Result = ['a', 'b', 'c', 'd', 1, 2, 3, 4]
 ```
@@ -48,10 +46,7 @@ Next, `filterfalse` iterates through a collection of elements, and, given a bool
 ```python
 numbers = [1, 2, 3, 4, 5, 6, 7, 8]
 
-print(
-  list(
-    itertools.filterfalse(
-      lambda x: 2 < x < 7, numbers)))
+print(list(itertools.filterfalse(lambda x: 2 < x < 7, numbers)))
 
 # Result = [1, 2, 7, 8]
 ```
@@ -62,9 +57,7 @@ Finally, `compress()`, which takes two collections, a and b, and returns only th
 numbers = [1, 2, 3, 4, 5, 6, 7, 8]
 boolean = [1, 0, 1, 0, 1, 0, 1, 0]
 
-print(
-  list(
-    itertools.compress(numbers, boolean)))
+print(list(itertools.compress(numbers, boolean)))
 
 # Result: [1, 3, 5, 7]
 ```
@@ -86,26 +79,18 @@ discounts = [-30, -100, -35, -85, -15]
 isInSale = [1, 0, 1, 1, 1]
 salePrices = []
 
-discountIterator =
-iter(
-  itertools.???(
-    discounts, isInSale))
+discountIterator = iter(itertools.???(discounts, isInSale))
 
-fullPricesInSale =
-itertools.compress(prices, isInSale)
+fullPricesInSale = itertools.compress(prices, isInSale)
 
 def f(x):
   price = x + next(discountIterator)
   salePrices.append(price)
   return(price <= 0)
 
-print(
-  list(
-    itertools.???(
-      lambda x: f(x), fullPricesInSale)))
+print(list(itertools.???(lambda x: f(x), fullPricesInSale)))
 
-print(
-  list(salePrices))
+print(list(salePrices))
 ```
 
 - `compress`
@@ -125,16 +110,10 @@ What is the result of the following code execution?
 ```python
 import itertools;
 
-names = ['Tom', 'Sadiq', 'Lars',
-          'Lee', 'Jean']
+names = ['Tom', 'Sadiq', 'Lars', 'Lee', 'Jean']
 boolean = [1, 0, 1, 1, 0]
 
-print(
-  list(
-    itertools.islice(
-      itertools.cycle(
-        itertools.compress(
-          names, boolean)), 0, 6)))
+print(list(itertools.islice(itertools.cycle(itertools.compress(names, boolean)), 0, 6)))
 ```
 
 ???