# Remainder - modular arithmetic

# systematically restrict computation to a range

# long division - divide by a number, we get a quotient plus a remainder

# quotient is integer division //, the remainder is % (Docs)

# problem - get the ones digit of a number

num = 49

tens = num // 10

ones = num % 10

print tens, ones

print 10 * tens + ones, num

# application - 24 hour clock

# http://en.wikipedia.org/wiki/24-hour_clock

hour = 20

shift = 8

print (hour + shift) % 24

# application - screen wraparound

# Spaceship from week seven

width = 800

position = 797

move = 5

position = (position + move) % width

print position

# Data conversion operations

# convert an integer into string - str

# convert an hour into 24-hour format "03:00", always print leading zero

hour = 3

ones = hour % 10

tens = hour // 10

print tens, ones, ":00"

print str(tens), str(ones), ":00"

print str(tens) + str(ones) + ":00"

# convert a string into numbers using int and float

# Python modules - extra functions implemented outside basic Python

import simplegui # access to drawing operations for interactive applications

import math # access to standard math functions, e.g; trig

import random # functions to generate random numbers

# look in Docs for useful functions

print math.pi