Как создать варьируемую в Python

x = 5
y = "John"

x = 4       # x is of type int
x = "Sally" # x is now of type str

x = str(3)    # x will be '3'
y = int(3)    # y will be 3
z = float(3)  # z will be 3.0
Asif Iqbal Paracha