On 07/26/2013 07:22 AM, Saad Javed wrote:
I'm trying to understand how this code works. I've commented the line
that I can't seem to understand. How did the guy come up with this?
#!/usr/bin/env python
import random
#rock > scissor > paper > rock
WEAPONS = 'Rock', 'Paper', 'Scissors'
for i in range(0, 3):
print "%d %s" % (i + 1, WEAPONS[i])
player = int(input ("Choose from 1-3: ")) - 1
cpu = random.choice(range(0, 3))
print "%s vs %s" % (WEAPONS[player], WEAPONS[cpu])
if cpu != player:
if (player - cpu) % 3 < (cpu - player) % 3: #How does this line work?
I'm not sure what aspect of it you're puzzled about, but % is the modulo
operator. It produces the remainder upon integer division. So we're
effectively dividing by 3, and keeping only the remainder, which will be
0, 1, or 2.
It will only be zero if cpu==player, but we've already tested that. So
the only two cases are 1 and 2. A little experimenting will show you
that if the first part( (player-cpu)%3 ) is 1, the second will be 2, and
vice versa.
So the statement could be simplified to:
if (player - cpu) % 3 == 1:
Now is it clear?
print "Player wins"
else:
print "CPU wins"
else:
print "tie!"
BTW, that input statement should be raw_input, since you're running it
on Python 2.x.
--
DaveA
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