python: refine notes

Programming_Languages/Python/Syntax/Iterating_through_complex_data_structures_in_Python.md

@@ -89,7 +89,7 @@ print(people)
 # Output: [['Alice', 30], ['Bob', 25], ['Clare', 35], ['Dave', 28]]
 ```
 
-### Updating a value within an element of a list of lists
+### Updating an inner value within a multidimensional list
 
 In the following example we have a list of the following structure:
 
@@ -101,12 +101,18 @@ data = [
 ]
 ```
 
-Below we use [list comprehension](/Programming_Languages/Python/Syntax/List_comprehension.md) to convert the first element of each iner list from a Unix timestamp to a readable string:
+Below we use [map](/Programming_Languages/Python/Syntax/Map_and_filter_in_Python.md) and a [lambda function](/Programming_Languages/Python/Syntax/Lambdas_in_Python.md) to convert the first element of each iner list from a Unix timestamp to a readable string:
 
 ```py
  readable_date = list(map(lambda i: [convert_timestamp(i[0])] + i[1:], date))
 ```
 
+We could also use [list comprehension](/Programming_Languages/Python/Syntax/List_comprehension_etc.md) to achieve the same outcome:
+
+```py
+readable_date = [[convert_timestamp(i[0])] + i[1:] for i in data]
+```
+
 ### Filter elements in a multidimensional list
 
 Say we have the following data structure:

Programming_Languages/Python/Syntax/List_comprehension.md

@@ -1,23 +0,0 @@
----
-categories:
-  - Programming Languages
-tags: [python]
----
-
-# List comprehension
-
-> List comprehension is an older feature of Python. Now the same functionality can be achieved with greater concision using functional methods like `map` and `filter`. But you may see it used in older code.
-
-```python
-values = [1, 2, 4, 6, 8, 9]
-
-new_values = [i + 1 for i in values]
-print('new_values', new_values)
-# new_values [2, 3, 5, 7, 9, 10]
-new_list = [item + 1 for item in values if item % 2 == 0]
-
-print('new_list:', new_list)
-# new_list: [3, 5, 7, 9]
-```
-
-// TODO: Compare with how the same would be achieved with lambdas

Programming_Languages/Python/Syntax/List_comprehension_etc.md

@@ -0,0 +1,74 @@
+---
+categories:
+  - Programming Languages
+tags: [python]
+---
+
+# List comprehension
+
+List comprehension is a syntactic shorthand for applying a function to each element in a list without explicitly using loop syntax.
+
+Since its introduction to the language, the same functionality has become achievable by using functional methods like [`map` and `filter`](/Programming_Languages/Python/Syntax/Map_and_filter_in_Python.md) utilising [lambdas](/Programming_Languages/Python/Syntax/Lambdas_in_Python.md) however list comprehension is often more straightforward and easier to read.
+
+## Syntax
+
+Here is a basic example which applies `+ 1` to each integer in a list:
+
+```python
+values = [1, 2, 4, 6, 8, 9]
+
+new_values = [i + 1 for i in values]
+print('new_values', new_values)
+# new_values [2, 3, 5, 7, 9, 10]
+```
+
+The basic syntax is as follows:
+
+```
+new_list  = [expression for each member in an iterable]
+```
+
+- The _expression_ can be the member itself, a call to a method, or any other valid expression that returns a value. In the example above, the expression `i + i` adds one to each member value.
+
+- The _member_ is the object or value in the list or iterable. In the example above, the member value is _i_.
+
+- The _iterable_ is a list, set, dictionary or any other object that can return its elements one at a time. In the example above, the iterable is each value in `values`.
+
+This is a much more condensed way of achieving the same outcome with a traditional loop:
+
+```py
+values = [1, 2, 4, 6, 8, 9]
+new_list = []
+for i in values:
+  values.append(i+1)
+```
+
+### Another example
+
+In the following example, we apply list comprehension with a `in range` loop structure:
+
+```py
+new_list = [i * i for i in range(10) ]
+print(new_list)
+# [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
+
+```
+
+### Adding a condition
+
+We can apply a
+
+```py
+new_list = [item + 1 for item in values if item % 2 == 0]
+
+print('new_list:', new_list)
+# new_list: [3, 5, 7, 9]
+```
+
+// Add example of how a simple filter could be applied without any execution on each element
+
+// TODO: Compare with how the same would be achieved with lambdas
+
+## Dictionary comprehension
+
+// TODO: Add note on dictionary and set comprehension