Using Python’s tuple packing and unpacking to switch 2 variables

Tuple is somehow similar to a List in Python except that the elements in a tuple is immutable (cannot be change or modified throughout the whole program). Tuple is a read-only List.

#this is an empty tuple.
t0 = ()

#this is a tuple.
t1 = (1, 2, 3)

#this is also a tuple.
t2 = 1, 2, 3

#these are  single element tuples.
#single element tuples must have #trailing comma. 
t3 = (1, )
t4 = 1, 

Using tuple packing and unpacking method to swap 2 variables without using a 3rd variable.

a = 1
b = 2


#swap variables using tuple packing and unpacking
a,b = b,a

print('After swapping...')


The right hand side of the equation is assigning the tuple (b,a) to (2,1). This is call packing. The left hand side is assigning variable ‘a’ to 2 and variable ‘b’ to 1. Putting the elements of a tuple to variables is call unpacking. Number of variables on LHS must be equal to number of elements in the tuple on the RHS