How to fix TypeError: 'type' object is not subscriptable?

Question

Python

with open('input.txt', 'r') as f:
    num = list(map(int, f.read().split()))

Here is my code. And it turns out that the data is written to a tuple, and I need to edit the list. But if I do this, num = list(map[int, f.read().split()]) that is, I rewrite it in a regular list, then it writes an error . I couldn't find an answer on the internet that worked for me.... TypeError: 'type' object is not subscriptable

Answer 1

Ufff. Here we are talking about the basics of Python syntax.
Your first code does the following.

num = list( #построить список из последовательности
    map( #вызываем функцию map()
        int, #первый параметр
        f.read().split() #второй параметр
    )
)

And the second code does (or rather tries) this:

num = list( #построить список из последовательности
    map[ #обращаемся к объекту map и пытаемся получить значение по ключу
        int, #первый элемент кортежа-ключа
        f.read().split() #второй элемент кортежа-ключа
    ]
)

Since map is not a dictionary or similar collection, this of course doesn't work, and generates exactly the error you specified.
I don’t understand where the idea came from that you can simply replace parentheses with square brackets in a function call if they have completely different semantics.
Well, yes, there can be nothing but a list in the output, since the result of the map () operation (and this will be a generator object) is explicitly converted into a list.
In general, the above was correctly advised - read the textbook, the same Mark Lutz, "Learning Python", at least the 4th edition. At least such errors will disappear.