Add input and output for code examples (#18646)

client/src/pages/guide/english/python/python-f-strings/index.md

@@ -8,22 +8,42 @@ The use of f-string allows the programmer to dynamically insert a variable into
 
 To perform these dynamic behaviours within an f-string we wrap them inside curly brackets within the string, and prepend a lower case f to the beginning of the string (before the opening quote.
 
-### Examples
+## Examples
-1. Dynamically inserting a variable into a string at runtime:
+### Dynamically inserting a variable into a string at runtime:
+
+#### Input
+
 ```python
 name = 'Jon Snow'
 greeting = f'Hello! {name}'
 print(greeting)
 ```
 
-2. Evaluate an expression in a string:
+#### Output
+
+```
+Hello! Jon Snow
+```
+
+### Evaluate an expression in a string:
+
+#### Input
+
 ```python
 val1 = 2
 val2 = 3
 expr = f'The sum of {val1} + {val2} is {val1 + val2}'
 print(expr)
 ```
-3. Calling a function and inserting output within a string:
+
+#### Output
+```
+The sum of 2 + 3 is 5
+```
+
+### Calling a function and inserting output within a string:
+
+#### Input
 ```python
 def sum(*args):
     result = 0
@@ -34,7 +54,14 @@ To perform these dynamic behaviours within an f-string we wrap them inside curly
 func = f'The sum of 3 + 5 is {sum(3, 5)}'
 print(func)
 ```
- 4. Joining the contents of a collection within a string:
+
+#### Output
+```
+The sum of 3 + 5 is 8
+```
+### Joining the contents of a collection within a string:
+
+#### Input
 
 ```python
 fruits = ['Apple', 'Banana', 'Pear']
@@ -42,5 +69,11 @@ To perform these dynamic behaviours within an f-string we wrap them inside curly
 list_str = f'List of fruits: {", ".join(fruits)}'
 print(list_str)
 ```
+
+#### Output
+```
+List of fruits: Apple, Banana, Pear
+```
+
 ### Sources
 https://www.python.org/dev/peps/pep-0498/