Question

what does the method readline() returns

Answer 1

It does not return anything but it reads the line if characters

Answer 2

The method readline() is a function/method that reads one whole line from the file. A trailing newline character is stored in the string and is kept with the file.

In the presence of the size parameter and if it is non-negative, it is a maximum byte count including the trailing newline.

In case a line is incomplete, then it may be returned.

An empty string is returned only when EOF is encountered immediately.