When I assign a list to variable why Pycharm give me a prompt that is “this list creation could be rewritten as a list literal”?

Check your code to make sure you don't have lst somewhere else as lst=[].

If you type the following:

lst= []
# more code
lst = [1, 2, 3, 4]

You'll receive the prompt you got. You won't run into problems if you keep it that way but it's bad practice.

In those two cases you are using a function to change the variable: list() and append(). In the previous one where you're just redefining the variable explicitly.

Another improper example:

a = 7
# some code that has nothing to do with "a" or uses it
a = 8

Just set a = 8 to begin with. No need to store a = 7.