How to append variable in Python code example

Example 1: python how to add one list to another list

# Basic syntax:
first_list.append(second_list) # Append adds the the second_list as an
#	element to the first_list
first_list.extend(second_list) # Extend combines the elements of the 
#	first_list and the second_list

# Note, both append and extend modify the first_list in place

# Example usage for append:
first_list = [1, 2, 3, 4, 5]
second_list = [6, 7, 8, 9]
first_list.append(second_list)
print(first_list)
--> [1, 2, 3, 4, 5, [6, 7, 8, 9]]

# Example usage for extend:
first_list = [1, 2, 3, 4, 5]
second_list = [6, 7, 8, 9]
first_list.extend(second_list)
print(first_list)
--> [1, 2, 3, 4, 5, 6, 7, 8, 9]

Example 2: how to append string to another string in python

# Concatenation
string1 = "str"
string2 = "ing"
string3 = string1 + string2
# string3 is str + ing which is 'string'
# OR
print(string1 + string2)            # prints 'string' 

# Format
string3 = f"{string1}{string2}"     # prints 'string'

Example 3: append a list to another list as element

a = ['Jon', 'janni', 'Jannardhan']
b = ['28', '29', '30']
a.append(b)
print(a)
a.pop()
a.extend(b)
print(a)

Example 4: how to append variable python

volumeA = 100
volumeB = 20
volumeC = 10

vol = []

vol.append(volume*)