append to a varaible in python code example

Example 1: 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 2: how to append variable python

volumeA = 100
volumeB = 20
volumeC = 10

vol = []

vol.append(volume*)