如何使用用户输入从文件中删除内容

Question

I have created a file with content. The problem is that I know how to add things with append but I don't know how to remove things from the file with a user input.

The code is, the results variable is dictionary:

    while True:
    remover = int(input("What results do you want to remove "))

    for line in enumerate(results, start = 1):
        line.remove(remover)
        print("{}".format(remover) + " is removed")

Would appreciate some help

Answer 1

This seems like something that lends itself pretty well for a list comprehension.

Assuming that results is a list of all the current results Please see the example below:

while True:
    remover = input("What results do you want to remove ")
    results = [line for line in results if line != remover]
    print("{}".format(remover) + " is removed")
    print("List currently has the following elements {}".format(results)

In the example below, for every iteration of the loop:

• The user is asked for input on what to remove
• A new list is created and put in 'results' by using a list comprehension that creates a new list out of elements that do not match with whatever is in 'remover'
• A message is shown explaining what was removed and another that prints the current list

For more information on how list comprehensions work, please see: https://www.pythonforbeginners.com/basics/list-comprehensions-in-python

---

If however you just want to get your example to work, you can refactor it into this:

while True:
remover = int(input("What results do you want to remove "))

    for line in results:
        if line == remover:
            results.remove(remover)
            print("{}".format(remover) + " is removed")

What I changed here:

1. I've moved your for statement into the while block, since I assume that with every iteration you want this to happen (why the while was there), additionally because you used a while(true) you would never execute the for block
2. I've changed the for statement for a foreach since this simplifies things a lot.

Please note that if you're not working with a list of integers, but strings you need to remove the typecasting to an int