我怎样才能删除“”和 . 从列表中的数据

Question

So i have this college python project that asks me to make a program to manage an inventory, my question basically is that whenever I try to convert the price and the quantity again to floats this exception rase, so how can I convert them so I can make further process on them? note that I tried to use .strip but it didn't work

this is the error:

float_price = float(i)

ValueError: could not convert string to float: '.'

this is the code that I have issues with:

from tabulate import tabulate
def read_data():
    file = open("inventory.txt", "r")
    list_of_lists = []
    for line in file:
        stripped_line = line.strip()
        line_list = stripped_line.split()
        list_of_lists.append(line_list)

    updated_list = list_of_lists[1:]
    file.close()
    return updated_list

def list_data():

    updated_list = read_data()
    
    index = 0
    price = 0
    quantity = 0
    j = 0
    while j < len(updated_list):
        for i in updated_list[1][4]:
            float_price = float(i)
            price += float_price

            
    
    print(price)
    
    
    header = ['MAKE', 'MODEL', 'PART ID', 'PART NAME', 'PRICE', 'QUANTITY']
    print(tabulate(updated_list, headers=header))    

    



list_data()

this is the code to add data to the file:

def input_parts():
    #Taking the parts input from the user
    try:
        make = input("Enter the make: ")
        model = input("Enter the model: ")
        part_id = input("Enter part_id: ")
        part_name = input("Enter part name: ")
        price = float(input("Enter price:QR "))
        quantity = int(input("Enter quantity: "))
    except ValueError:
        print("BOTH PRICE AND QUANTITY CAN NOT BE LETTERS, PLEASE RE-ENTER THE RIGHT DATA")
    else:
        #transferring both price and quantitiy to strings
        price = str(price)
        quantity = str(quantity)
        list = ['\n' + make,model,part_id,part_name,price,quantity]
        return list


#This function is to save the parts information to a file
def add_parts():
    #Assignning this sentinal to make the loop repeat if the user didn't want to save
    sentinal = True
    while sentinal is True:
        #Assigning the values of the inputs function to a variable
        parts = input_parts()
        #Validating user's unput
        try:
            #Asking the user if he wants to save the information to the file
            save = input("Save? (Y/N) or Q to quit ")
        except TypeError:
            print("YOU CANNOT SAVE WRONG DATA IN THE FILE PLEASE RE-ENTER YOUR DATA")
        else:
            pass
        #A boleen function to import the data to the file if the boleen is true
        if save.lower() == 'y':
            outfile = open('inventory.txt',"a")
            #Validating user's input
            try:
                #Using a for loop to print the information in the file
                for i in parts:
                    outfile.write(i+ '\t')
            except TypeError:
                print("YOU CAN NOT SAVE WRONG DATA FILES!!!")
                break
            else:
                pass
            outfile.close
            print("....Record saved.")
            sentinal = False
        #Using an elif statment to enable the user to re input his data
        elif save.lower() == 'n':
            sentinal = True
        #Using an elif statment to quit if the user wants to
        elif save.lower() == 'q':
            break
        #Using else statment to tell the user no input a valid choice
        else:
            print("PLEASE ENTER (Y/N) IF YOU WANT TO SAVE!!!!")
            print("YOUR DATA HAS NOT BEEN SAVED")
            print("PLEASE RE-ENTER YOUR DATA AND TRY AGAIN.")
            sentinal = True

add_parts()

Answer 1

as error message indicates '.' is string and it cannot be converted to float so raises error.. it depends what you want to do with such situation you can use try except as.

from tabulate import tabulate
def read_data():
    file = open("inventory.txt", "r")
    list_of_lists = []
    for line in file:
        stripped_line = line.strip()
        line_list = stripped_line.split()
        list_of_lists.append(line_list)

    updated_list = list_of_lists[1:]
    file.close()
    return updated_list

def list_data():

    updated_list = read_data()
    
    index = 0
    price = 0
    quantity = 0
    j = 0
    while j < len(updated_list):
        for i in updated_list[1][4]:
            try:
               float_price = float(i)
               price += float_price
            except ValueError as e:
               print('Value Error')
   
            

            
    
    print(price)
    
    
    header = ['MAKE', 'MODEL', 'PART ID', 'PART NAME', 'PRICE', 'QUANTITY']
    print(tabulate(updated_list, headers=header))    

    



list_data()