existing_set = set(existing_lines)

The set constructor in Python, written as set(), is a built-in function used to create a set object, which is an unordered collection of unique elements. When you pass an iterable, such as a list, tuple, or the lines of a file, into this constructor, Python...

]

The closing square bracket, represented by the glyph “]”, has a rich history that evolved alongside the development of modern punctuation and typography. While basic parenthetical marks can be traced back to the medieval period, the specific form of the...