[Python] I'm asking you a question about the 3-line code for beginners! (list.append(input) infinite input phenomenon)

The questioner is misunderstanding.

It doesn't repeat itself indefinitely.[wl.append('hello') for t in wl] The cursor is blinking for the time it takes for the code to run...The questioner thinks the input keeps coming in.

Run the program and look at the memory state. It's going to keep increasing.In a few minutes, the process will end with a memory error.

(py36) allinux@~$ python -V
Python 3.6.2

(py36) allinux@~$ cat abcd.py
wl = []; nl = []

[wl.append(input()) for t in range(int(input()))]

#[wl.append('hello') for t in wl]

(py36) allinux@~$ python abcd.py
3
aaa
bbb
ccc
(py36) allinux@~$

Please correct the test as below and try it.

wl = []; nl = []

[wl.append(input('Input a string: ')) for t in range(int(input('Input a Number: ')))]

[wl.append('hello') for t in wl]

[wl.append('hello') for t in wl]

For t in wl is to get elements from wl one by one by one. That is, if there are 3 elements, you will look up 3 elements. However, every iteration calls the wl.append again to add elements to the wl, which is eventually an infinite iteration.

[wl.append('hello') for t in range(len(wl))]

Gets the list size of the time point when called by len(wl). len(w) is not affected by wl.append because it is called only once.