how to write varaible in python in string code example

Example 1: how to use variables in string in python

#Use f-string
#Example:

x = 2
y = f'This is a string using variable x: {x}'
print(y)

#Output: 
#This is a string using variable x: 2

Example 2: how to give a string value variable in python

foo = "bar"
exec(foo + " = 'something else'")
print bar
something else