这是什么意思：AttributeError：'str'对象没有属性'write'

Question

When I go to run this code, I get the error above. I would understand if it was because one of my objects haven't been identified as strings but the error appears on the first file_name.write()

def save_itinerary(destination, length_of_stay, cost):
    # Itinerary File Name
    file_name = "itinerary.txt"

    # Create a new file
    itinerary_file = open('file_name', "a")

    # Write trip information
    file_name.write("Trip Itinerary")
    file_name.write("--------------")
    file_name.write("Destination: " + destination)
    file_name.write("Length of stay: " + length_of_stay)
    file_name.write("Cost: $" + format(cost, ",.2f"))

    # Close the file
    file_name.close()

Answer 1

You should be using itinerary_file.write and itinerary_file.close , not file_name.write and file_name.close .

Also, open(file_name, "a") and not open('file_name', "a") , unless you're trying to open a file named file_name instead of itinerary.txt .

Answer 2

An attribute error means that the object your trying to interact with, does not have the item inside it you're calling.

For instance

>>> a = 1

>>> a.append(2)

a is not a list, it does not have an append function, so trying to do this will cause an AttributError exception

when opening a file, best practice is usually to use the with context, which does some behind the scenes magic to make sure your file handle closes. The code is much neater, and makes things a bit easier to read.

def save_itinerary(destination, length_of_stay, cost):
    # Itinerary File Name
    file_name = "itinerary.txt"
    # Create a new file
    with open('file_name', "a") as fout:
        # Write trip information
        fout.write("Trip Itinerary")
        fout.write("--------------")
        fout.write("Destination: " + destination)
        fout.write("Length of stay: " + length_of_stay)
        fout.write("Cost: $" + format(cost, ",.2f"))