Function won't work, says it's not defined?-CodePudding

I am trying to use this code, to calculate an area cost. I am using the functions option but it says that cost is not defined, I did define it.

def space():
    """ This function will calculate the area of floor, that needs 
    flooring. """
    
    # asking for variables
    length =int(input('Please enter the length of the room in meters: '))
    width =int(input('Please enter the width of the room in meters: '))
    
    area=length*width
    
    return area

def flooring():
    """This function will take the flooring chosen by the user and will
    return the cost of the square meter."""
    
    while True:
        # asking for variables
        opt=int(input('Please select type of flooring: '))
        if (opt>=1 and opt<=5):
            break
        
    if (opt==1):
        price=18.75
    ...        
        
    return price
    
def cost():
    """This will calculate the cost of the flooring, and other costs, and
    will display them, aligned."""
    print(price)
    matCost=area*price
    print("$",matCost)  

###
### MAIN PROGRAM
###

while True:
    ...
    
    space()
    print()
    
    print('Types of Flooring')
    print()
    print('                Cost per sq.m.')
    print('1. Low Pile Carpet     $18.75')
    ...
    
    flooring()
    print()
    cost()

The error says but I thought I already defined it. With the if statement for the opt, I had thought that I already defined.

Traceback (most recent call last):
  File"main.py", line 80 in <module>
    cost()
  File"main.py", line 52 in <module>
    print(price)
NameError: name 'price' is not defined

CodePudding user response：

I think you just forgot to add price on the def cost():

def cost(price):
    """This will calculate the cost of the flooring, and other costs, and
    will display them, aligned."""
    print(price)
    matCost=area*price
    print("$",matCost)  

price_result = flooring()
cost(price_result)

CodePudding user response：

Because the price variable is defined inside of a function, It is not global. Instead of attempting to call the price variable directly, you must call to the flooring method which returns said price variable.

def cost():
    """This will calculate the cost of the flooring, and other costs, and
    will display them, aligned."""
    price = flooring()

    # The area variable is also not defined outside of the space method so it would be a good idea to add this as well.
    area = space()
    print(price)
    matCost=area*price
    print("$",matCost)