在python中调用库函数

Question

Case I: In some cases, I use the library name to call some set of function ie, np.median().
Case II: And in some cases, I use the variable name and library name to call another set of function ie, np.mean(heights) or heights.mean().
In case II, I am able to use both library name and variable name. In case I, only library name works.

My doubt is how to differentiate these tow sets of functions. If I am wrong in anyway, please clear my thoughts. (here i am referring to python language)

thank you.

Answer 1

In the first case you're calling a method (function) of the library. Libraries are usually class instances or collections of functions within a module.

In the second example instead, you're again calling a function from the module but in this case it returns a ndarray (a numpy list basically) which itself has some methods that can be called on it.