import csv

FILENAME = "trip.csv"

def save_data(miles, gallons, mpg):
    header = ["Distance", "Gallons", "MPG"]
    data = [miles, gallons, mpg]
    with open(FILENAME, 'w', newline="") as file:
        writer = csv.writer(file)
        writer.writerow(header)
    with open(FILENAME, 'a', newline="") as file:
        writer = csv.writer(file)
        writer.writerows(data)

def display_title():
    print("The Miles Per Gallon program.\n")


def calculate_totals(miles, gallons, cost):
    mpg = miles / gallons
    cost_per_mile = miles / cost
    total_fuel_cost = gallons * cost
    display_data(mpg, cost_per_mile, total_fuel_cost, gallons, miles)

def display_data(mpg, cost_per_mile, total_fuel_cost, gallons, miles):
    print()
    print(f"MPG on this trip is {mpg} gallons.")
    print(f"Cost per mile was ", cost_per_mile)
    print(f"Total fuel spent was ", total_fuel_cost)
    print()
    save_data(miles, gallons, mpg)

def main():
    display_title()
    
    choice = "y"
    while choice.lower() == "y":
        miles = float(input("Enter miles driven: "))
        gallons = float(input("Enter gallons used: "))
        cost = float(input("Enter cost per gallon: "))
        calculate_totals(miles, gallons, cost)
        choice = input("Do you wish to enter a new entry: y/n ")

if __name__ == "__main__":
    main()

I was trying to get an output into a CSV that had Distance, Gallons and MPG as a header with the rows underneath keeping user input data. I finally figured out how to make the header but now I am getting a float error and nothing I try seems to get rid of it. Any help would be appreciated.

CodePudding user response：

The problem is that you are using writerows on the second call, which expects an iterable of iterables of values, whereas you're only passing it an iterable of values. There's two ways to fix it:

1. Use writerow:

writer.writerow(data)

2. Actually pass in an iterable of iterables, most easily by creating another list:

writer.writerows([data,])