code that opens a files, uses a loop to get numbers form user and writes the numbers to the file, th-CodePudding

I'm trying to solve the following problem:

Write code that does the following: opens an output file with the filename number_list.txt, uses a loop to get numbers from the user, and writes the numbers to the file, then closes the file.

Here's what I have:

while True:
    num = int(input("enter a number, to stop enter 0"))
    myflie = open("number_list.txt", "w")
    myflie.write(str(num))
    if num == 0:
        break
    myflie.close()

The code doesn't give me any errors, but when I check the file, only one number gets written to it.

CodePudding user response：

Use a to write to a file without deleting the contents first, also move the check before the write operation if you don't want '0' to be written as well.

while True:
    num = int(input("enter a number, to stop enter 0"))
    if num == 0:
        break

    with open('number_list.txt', 'a') as f:
        f.write(str(num))

    # if you want it like this
    # f = open('number_list.txt', 'a')
    # f.write(str(num))
    # f.close()

CodePudding user response：

The mode "w" overwrites the contents of the file whenever you write to it. It seems as if you want to append to it, and so, use the mode "a". Also, do file operations using with the with statement. Even if the writing process throws an exception, the file will surely close.

while True:
    num = int(input("Enter a number, to stop enter 0:"))
    if num == 0: break
    
    with open('number_list.txt', 'a') as f:
        f.write(str(num))

If you think having a file operation for every run of the loop is too much, you can append the inputs in a list and do a writelines after the user breaks out of the loop.

nums = []
while True:
    num = int(input("Enter a number, to stop enter 0:"))
    if num == 0:
        break
    else:
        nums.append(num)

with open('number_list.txt', 'a') as f:
    f.writelines(nums)