CODEWITHSUNDEEP
python
vkumar
vkumar

Reputation: 921

How to convert '*' to *

I am making a math quiz game in python, where the computer selects 2 numbers and 1 symbol from a list and prints it, then the user answers the question. In my list with the symbols, I have the math symbols as strings, but when I want the computer to get the answer, It can't, because the symbols are strings. How do I convert the '*' string to the * symbol used in math? Any help is appreciated, I will post what I have of the game so far as well.

import random
import time
import math

symbols = ('*', '+', '-', '/')
count = 0
def intro():
    print("Hi")
    print("Welcome to the math quiz game, where you will be tested on addition")
    print("Subtraction, multiplication, and division, and other math skills")
    time.sleep(3)
    print("Lets begin")

def main(count):
        number_1 = random.randrange(10,20+1)
        number_2 = random.randrange(1,10+1)
        symbol = (random.choice(symbols))
        print("Your question is: What is %d %s %d") %(number_1, symbol, number_2)


main(count)

Upvotes: 0

Views: 125

Answers (3)

Lukas Graf
Lukas Graf

Reputation: 32590

Use the operator module and map the operators to your desired symbols:

import operator
import random

OPS = {
    '+': operator.add,
    '-': operator.sub,
    '*': operator.mul,
    '/': operator.truediv,
}

op_symbol = random.choice(OPS.keys())
operand1 = random.randint(1, 10)
operand2 = random.randint(1, 10)

formula = "{} {} {} = ?".format(operand1, op_symbol, operand2)
operator = OPS[op_symbol]
result = operator(operand1, operand2)

print "Question: {}".format(formula)
print "Result: {}".format(result)

Note that for Python 2.x the / operator (operator.div) does integer division - hence I used operator.truediv instead because otherwise you'd get surprising results when dividing integers.

Upvotes: 6

willeM_ Van Onsem
willeM_ Van Onsem

Reputation: 476624

You can use the eval functionality to evaluate a string as a command:

result=eval(str(number_1)+str(symbol)+str(number_2))

In that case result will get the value of the queried question.

However as @icktoofay says, always use eval with caution: if you don't use it properly it can have side effects (like eval("somecommand()")) or even worse, it can allow a user to insert python logic in your program: for instance eval(cmd) where the user can enter the command.

Upvotes: 3

freakish
freakish

Reputation: 56467

You have to give a meaning to those symbols. One way would be by realizing that each of these symbols is a function that takes two arguments. Thus you can do:

symbols = {
    '*': lambda x, y: x*y,
    '+': lambda x, y: x+y,
    '-': lambda x, y: x-y,
    '/': lambda x, y: x/y,
}

and then you can do

number_1 = random.randrange(10,20+1)
number_2 = random.randrange(1,10+1)
symbol = random.choice(symbols.keys())
operator = symbols[symbol]
result = operator(number_1, number_2)

Upvotes: 6

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