[None and Random Concepts]: Fixed Typos & Formatting

concepts/none/about.md

@@ -1,2 +1,3 @@
-# About
+# TODO:  Add about for this concept.
+
 

concepts/none/introduction.md

@@ -1,29 +1,33 @@
 # Introduction
 
-In Python, `None` is frequently used to represent the absence of a value -- a placeholder to define a `null` (empty) variable, object, or argument.
+In Python, `None` is frequently used to represent the absence of a value — a placeholder to define a `null` (empty) variable, object, or argument.
+
+If you've heard about or used a `NULL` or `nil` type in another programming language, then this usage of `None` in Python will be familiar to you.
+`None` helps you to declare variables or function arguments that you don't yet have values for.
+These can then be re-assigned to specific values later as needed:
 
-If you've heard about or used a `NULL` or `nil` type in another programming language, then this usage of `None` in Python will be familiar to you. `None` helps you to declare variables or function arguments that you don't yet have values for. These can then be re-assigned to specific values later as needed.
 
 ```python
 a = None
 print(a)
 #=> None
+
 type(a)
 #=> <class 'NoneType'>
 
-# Adding a Default Argument with `None`
+# Adding a default argument with `None`
 def add_to_todos(new_task, todo_list=None):
-  if todo_list is None:
-    todo_list = []
+    if todo_list is None:
+        todo_list = []  
     todo_list.append(new_task)
+
   return todo_list
-
 ```
 
-`None` will evaluate to `False` when used in a conditional check, so it is useful for validating the "presence of" or "absence of" a value - _any_ value -- a pattern frequently used when a function or process might hand back an error object or message.
+`None` will evaluate to `False` when used in a conditional check, so it is useful for validating the "presence of" or "absence of" a value — _any_ value — a pattern frequently used when a function or process might hand back an `error`, `object`, or message.
 
 ```python
 a = None
-if a: #=> a will be evaluated to False when its used in a conditional check.
+if a: #<-- a will be evaluated to False when it is used in a conditional check.
     print("This will not be printed")
 ```

concepts/random/about.md

@@ -1,9 +1,9 @@
 # About
 
-Many programs need (apparently) random values to simulate real-world events.
+Many programs need (_seemingly_) random values to simulate real-world events.
 
 Common, familiar examples include:
-- A coin toss: a random value from `('H', 'T')`.
+- A coin toss: a random value from `('Heads', 'Tails')`.
 - The roll of a die: a random integer from 1 to 6.
 - Shuffling a deck of cards: a random ordering of a card list.
 
@@ -18,7 +18,7 @@ We encourage you to explore the full `random` documentation, as there are many m
 
 ~~~~exercism/caution
 
-The `random` module should __NOT__ be used for security and cryptographic applications.
+The `random` module should __NOT__ be used for security or cryptographic applications.
 
 Instead, Python provides the [`secrets`][secrets] module.
 This is specially optimized for cryptographic security.
@@ -60,17 +60,17 @@ To avoid typing the name of the module, you can import specific functions by nam
 
 # Using choice() to pick Heads or Tails 10 times
 >>> tosses = []
->>> for side in range(10):
->>>    tosses.append(choice(['H', 'T']))    
+... for side in range(10):
+...    tosses.append(choice(['H', 'T']))    
 
 >>> print(tosses)
 ['H', 'H', 'H', 'H', 'H', 'H', 'H', 'T', 'T', 'H']
 
 
 # Using choices() to pick Heads or Tails 8 times
 >>> picks = []
->>> picks.extend(choices(['H', 'T'], k=8))
->>> print(picks)
+... picks.extend(choices(['H', 'T'], k=8))
+... print(picks)
 ['T', 'H', 'H', 'T', 'H', 'H', 'T', 'T']
 ```
 
@@ -94,8 +94,9 @@ Possible results from `randint()` _include_ the upper bound, so `randint(a, b)`
 
 # Select 10 numbers at random between 0 and 9 two steps apart.
 >>> numbers = []
->>> for integer in range(10):
->>>    numbers.append(random.randrange(0, 10, 2))
+... for integer in range(10):
+...    numbers.append(random.randrange(0, 10, 2))
+
 >>> print(numbers)
 [2, 8, 4, 0, 4, 2, 6, 6, 8, 8]
 
@@ -108,10 +109,10 @@ Possible results from `randint()` _include_ the upper bound, so `randint(a, b)`
 
 ## Working with sequences
 
-The functions in this section assume that you are starting from some [sequence][sequence-types], or other container.
+The functions in this section assume that you are starting from some [sequence][sequence-types] or other container.
 
 
-This will typically be a `list`, or with some limitations a `tuple` or a `set` (_a `tuple` is immutable, and `set` is unordered_).
+This will typically be a `list`, or with some limitations, a `tuple` or a `set` (_a `tuple` is immutable, and `set` is unordered_).
 
 
 
@@ -124,9 +125,10 @@ At its simplest, this might be a coin-flip:
 # This will pick one of the two values in the list at random 5 separate times 
 >>> [random.choice(['H', 'T']) for _ in range(5)]
 ['T', 'H', 'H', 'T', 'H']
+```
 
-We could accomplish essentially the same thing using the `choices()` function, supplying a keyword argument with the list length:
 
+We could accomplish essentially the same thing using the `choices()` function, supplying a keyword argument with the list length:
 
 ```python
 >>> random.choices(['H', 'T'], k=5)

concepts/random/introduction.md

@@ -1,9 +1,9 @@
 # Introduction
 
-Many programs need (apparently) random values to simulate real-world events.
+Many programs need (_seemingly_) random values to simulate real-world events.
 
 Common, familiar examples include:
-- A coin toss: a random value from `('H', 'T')`.
+- A coin toss: a random value from `('Heads', 'Tails')`.
 - The roll of a die: a random integer from 1 to 6.
 - Shuffling a deck of cards: a random ordering of a card list.
 - The creation of trees and bushes in a 3-D graphics simulation.
@@ -18,7 +18,7 @@ We encourage you to explore the full [`random`][random] documentation, as there
 
 ~~~~exercism/caution
 
-The `random` module should __NOT__ be used for security and cryptographic applications!!
+The `random` module should __NOT__ be used for security or cryptographic applications!!
 
 Instead, Python provides the [`secrets`][secrets] module.
 This is specially optimized for cryptographic security.
@@ -57,17 +57,17 @@ To avoid typing the name of the module, you can import specific functions by nam
 
 # Using choice() to pick Heads or Tails 10 times
 >>> tosses = []
->>> for side in range(10):
->>>    tosses.append(choice(['H', 'T']))    
+... for side in range(10):
+...    tosses.append(choice(['H', 'T']))    
 
 >>> print(tosses)
 ['H', 'H', 'H', 'H', 'H', 'H', 'H', 'T', 'T', 'H']
 
 
 # Using choices() to pick Heads or Tails 8 times
 >>> picks = []
->>> picks.extend(choices(['H', 'T'], k=8))
->>> print(picks)
+... picks.extend(choices(['H', 'T'], k=8))
+... print(picks)
 ['T', 'H', 'H', 'T', 'H', 'H', 'T', 'T']
 ```
 
@@ -89,10 +89,10 @@ Possible results from `randint()` _include_ the upper bound, so `randint(a, b)`
 
 ## `choice()` and `choices()`
 
-These two functions assume that you are starting from some [sequence][sequence-types], or other container.
-This will typically be a `list`, or with some limitations a `tuple` or a `set` (_a `tuple` is immutable, and `set` is unordered_).
+These two functions assume that you are starting from some [sequence][sequence-types] or other container.
+This will typically be a `list`, or with some limitations, a `tuple` or a `set` (_a `tuple` is immutable, and `set` is unordered_).
 
-The `choice()` function will return one entry chosen at random from a given sequence, and `choices()` will return `k` number of entries chosen at random from a given sequence.
+The `choice()` function will return one member chosen at random from a given sequence, and `choices()` will return a specified number of members (`k`) chosen at random from a given sequence.
 In the examples shown above, we assumed a fair coin with equal probability of heads or tails, but weights can also be specified.
 
 For example, if a bag contains 10 red balls and 15 green balls, and we would like to pull one out at random: