''' Purpose: considers the subltety of swapping variable values
'''

# get and echo inputs

reply  = input( 'Enter two words: ' )

w1, w2 = reply.split()

print( )
print( 'w1 =', w1 )
print( 'w2 =', w2 )

print()

# do only one way

# way 1
# swap the values of w1 and w2
remember_w1 = w1    # we are storing the value of w1 in another variable, so we don't lose it
w1 = w2             # we update w1 with the value of w2, so the old value of w1 is lost!!
# w2 = w1             # if we update w2 with w1, w1 now has the same value as w2, so same values
w2 = remember_w1    # remember_w1 holds the original value of w1, this is the value we want to update in w2
# this is an important concept in CS!

# swapping in the print statement does not change the values of the variables! You're just cheating :)

# way 2: the python way
# swapping both at the same time
# when you have 2 things on the left side, you must have 2 things on the right side
w1, w2 = w2, w1
# Right side: get the current value of w2, get the current value of w1
# Left side: put the current value of w2 into w1, put the current value of w1 into w2

# print results

print( 'After swapping' )

print()

print( 'w1 =', w1 )
print( 'w2 =', w2 )

n = 4
n = n + 1
# right side: find value of current of n = 4 --> + 1 --> evaluates to 5
# left side: puts 5 into n (updates n)