arithmeticbuilder.py

#!/usr/bin/env python2
# description: generate a series of arithmetic for teaching
# TODO 

import os
import sys
import random
import string

def generater(rang):
    a = ('+', '-')
    width = len(str(rang))
    op1 = random.randint(0, rang)
    op2 = random.randint(0, rang)
    op  = random.randint(0, 1)
    if op == 1 and op1 < op2:
        op1, op2 = op2, op1
    return string.join((string.rjust(str(op1), width), 
                        a[op], 
                        string.rjust(str(op2), width), 
                        '='), ' ')

def format(s):
    str = ''
    for ss in s:
        str += string.ljust(ss, 20)
    str += '\n'
    return str

def main():
    count = 100
    rang  = 100
    step  = 4
    r = open("test.txt", 'w')
    for index in range(0, count, step):
        exp = []
        for x in range(0, step):
            exp.append(generater(rang))
        r.write(format(exp))
    r.close()

if __name__ == '__main__':
    main()