在Python中明确声明变量类型

Question

I use pyscripter for coding, it supports auto-completion. So, when I say:

a = []
a.

It gives me all the list functions. similarly with strings I do b='' .

But for the file type, I have to use file. and choose the function and write its arguments and then replace file with the variable name.

Is there a way to declare a variable type explicitly in Python, so that my IDE can be more useful?

Answer 1

Python has no type declarations. Python 3 introduces something called function annotations , which Guido sometimes refers to as "the thing that isn't type declarations," because the most obvious use of it will be to provide type information as a hint.

As others have mentioned, various IDEs do a better or worse job at auto-completing.

Answer 2

万一你想在一个类型上调用方法...你总是可以在python控制台中使用dir（var）...

Answer 3

As of Python 3, you can explicitly declare variables by type:

x: int = 3

or:

def f(x: int):
    return x