Add input and output for code examples (#18646)

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

@@ -8,39 +8,72 @@ 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
-1. Dynamically inserting a variable into a string at runtime:
-    ```python
-    name = 'Jon Snow'
-    greeting = f'Hello! {name}'
-    print(greeting)
-    ```
+## Examples
+### Dynamically inserting a variable into a string at runtime:
 
-2. Evaluate an expression in a string:
-    ```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:
-    ```python
-    def sum(*args):
-        result = 0
-        for arg in args:
-            result += arg
-        return result
+#### Input
 
-    func = f'The sum of 3 + 5 is {sum(3, 5)}'
-    print(func)
-    ```
- 4. Joining the contents of a collection within a string:
+```python
+name = 'Jon Snow'
+greeting = f'Hello! {name}'
+print(greeting)
+```
 
-    ```python
-    fruits = ['Apple', 'Banana', 'Pear']
+#### 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)
+```
+
+#### Output
+```
+The sum of 2 + 3 is 5
+```
+
+### Calling a function and inserting output within a string:
+
+#### Input
+```python
+def sum(*args):
+    result = 0
+    for arg in args:
+        result += arg
+    return result
+
+func = f'The sum of 3 + 5 is {sum(3, 5)}'
+print(func)
+```
+
+#### Output
+```
+The sum of 3 + 5 is 8
+```
+### Joining the contents of a collection within a string:
+
+#### Input
+
+```python
+fruits = ['Apple', 'Banana', 'Pear']
+
+list_str = f'List of fruits: {", ".join(fruits)}'
+print(list_str)
+```
+
+#### Output
+```
+List of fruits: Apple, Banana, Pear
+```
 
-    list_str = f'List of fruits: {", ".join(fruits)}'
-    print(list_str)
-    ```
 ### Sources
 https://www.python.org/dev/peps/pep-0498/