But then again, unfortunately, Python's significant whitespace makes automatic indentation hard, because there are some edge cases that an editor cannot extract

But then again, unfortunately, Python's significant whitespace makes automatic indentation hard, because there are some edge cases that an editor cannot extract the actual intention by the programmer well. For example, if there is a code as: for i in range(10): if i % 2 == 0: print('hello') and I paste `print('world')` after that, there are at least three possibilities of the proper indentation of the line. It can match with `print('hello')`, or with `if`, or even with `for`. That's because Python encodes block information solely using whitespace. So, if the indentation changes, the actual meaning of the code also changes! In fact, that's why it is called "significant". You cannot automate it, just like you cannot automate writing code.