For example, we have two functions, len() and title(). Why do some functions/methods, in this case len(), requires us to use an argument in order for it to do its job, while some other functions/methods require us to use dot notation to do its job, in this case, title().

CodePudding user response：

.function(args) is a method. function(args) is a function.

A method is called on an object, and a function is simply, well, a function.

A function can be called by itself, but a method needs an object.

CodePudding user response：

One of them is a method inherited from the class of the instance, other one is a built-in function globally available.

You need to understand inheritance in programming to fully grasp this. I would recommend studying object oriented programming.

CodePudding user response：

As someone who embarked in this path not so long ago, I can relate to your question, as I asked similar questions as well.

IMO there is no set in stone way to know, this is a concept that you will understand more and more as you learn different methods/functions.

It's very similar to understanding masculine/feminine connotations of stuff in a new language.