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Python

Posted by Cheri Castro
Cheri Castro
226 Points

Ok, I keep getting this error, please help. ZeroDivisionError: float division by zero. Second try.

I posted this earlier and the answer I got back was that because I have number = 0 and that's why I'm getting the error. I thought because I have asked for a number input then shouldn't that be used as the number divisor? Please, give me some clues. I tried placing number = get_number() but that didn't work either.

def main():
    print("Welcome to the monthly gas and milage tracker.") 
    end_program = 'no'
    counter = 1
    number = 0
    cost_pergal = 0.0
    total_gal = 0.0
    total_cost = 0.0
    beginning_milage = 0.0
    ending_milage = 0.0
    total_miles = 0.0
    miles_pergal = 0.0
    display_info(counter, number, ending_milage, beginning_milage, total_gal, total_cost, total_miles, miles_pergal)

    while end_program == 'no':
      end_program, counter, number, cost_pergal, total_gal, total_cost, beginning_milage, ending_milage, total_miles, miles_pergal

      number = get_number()
      miles_pergal = get_mpg(number, cost_pergal, total_gal, total_cost, beginning_milage, ending_milage, total_miles, miles_pergal)

      end_program = input("Do you want to end the program?(Enter yes to end the program or no to continue with another calcualtion of miles per gallon).:") 

def get_number():
    number = int(input("How many months worth of gas do you want to calculate?: "))
    return number


def get_mpg(counter, number, cost_pergal, total_gal, total_cost, beginning_milage, ending_milage, total_miles, miles_pergal):
    for counter in range(number):
      cost_pergal = float(input("What was the cost per gallon?: "))
      total_gal = float(input("What were the total gallons?: "))
      total_cost = float(cost_pergal * total_gal)/int(number)
      beginning_milage = float(input("What was the beginning milage?: "))
      ending_milage = float(input("What was the ending milage?: "))
      return number, cost_pergal, total_gal, total_cost, beginning_milage, ending_milage, total_miles, miles_pergal

def display_info(counter, number, ending_milage, beginning_milage, total_gal, total_cost, total_miles, miles_pergal):
    total_miles = float(ending_milage - beginning_milage)/ int(number)
    miles_pergal = float(total_gal/ total_miles) * int(number)
    print("Your total cost was: " + total_cost)
    print("Your total miles traveled was: " + total_miles)
    print("Your total miles per gallon were: " + miles_pergal)

main()

3 Answers

Francis Obwogo
Francis Obwogo
14,982 Points
Francis Obwogo
Francis Obwogo
14,982 Points

The function display_info is called before the get_number function. This therefore means that the variable "number" is set to 0 during the function display_info call. You will end up getting a ZeroDivisionError: float division by zero from from the expression "total_miles = float(ending_milage - beginning_milage)/ int(number)".

Cheri Castro
Cheri Castro
226 Points

Ok, so can you tell me how to fix it? I tried naming number = get_number() but that didn't change the result. I tried not having int, in front of the equation. In other programs this method of having a number and requesting input for a number and then using whatever the input number for whatever equation. I don't understand why it isn't working this time.

Francis Obwogo
Francis Obwogo
14,982 Points
Francis Obwogo
Francis Obwogo
14,982 Points

def main(): print("Welcome to the gas and mileage tracker.")

# number of months
months = number_of_months()

# get tank capacity
tank_capacity = int(input("Please enter the volume of you car's tank in gallons: "))

# get gas used in a month
gas_per_month = int(input("Please enter the number of gallons used per month: "))

# get miles travelled on a full tank
miles_on_full_tank = int(input("Please enter the miles covered using a full tank of gas: "))

# get cost of gas per gallon
cost_per_gallon = int(input("Please enter the cost of gas per gallon: "))

# calculate mpg
mpg = get_mpg(miles_on_full_tank, tank_capacity)

# calculate the cost of gas per month
gas_cost_in_a_month = calc(gas_per_month, cost_per_gallon)

# calculate the cost of gas for months
gas_cost_for_months = calc(months, gas_cost_in_a_month)

# calculate distance
distance = mpg * gas_cost_for_months

# display info
display_info(gas_cost_for_months, distance, mpg)

def number_of_months(): number = int(input("How many months worth of gas do you want to calculate? ")) return number

def calc(foo, foobar): return foo * foobar

def get_mpg(foo, foobar): return foo / foobar

def display_info(cost, miles_travelled, mpg): print("Your total cost will be: ", cost) print("Your total miles traveled will be: ", miles_travelled) print("Your miles per gallon were: ", mpg)

if name == 'main': main()

Cheri Castro
Cheri Castro
226 Points

I don't understand what foo and foobar are. I've never used those before.

Francis Obwogo
Francis Obwogo
14,982 Points
Francis Obwogo
Francis Obwogo
14,982 Points

def calc(foo, foobar): return foo * foobar

foo and foobar are parameters for the function calc that returns the product of two values. You can rename them to any name that you like.