Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
478 views
in Technique[技术] by (71.8m points)

python - mypy, type hint: Union[float, int] -> is there a Number type?

mypy is really handy and catches a lot of bugs, but when I write "scientific" applications, I often end up doing:

def my_func(number: Union[float, int]):
    # Do something

number is either a float or int, depending on the user's input. Is there an official way to do that?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Use float only, as int is implied in that type:

def my_func(number: float):

PEP 484 Type Hints specifically states that:

Rather than requiring that users write import numbers and then use numbers.Float etc., this PEP proposes a straightforward shortcut that is almost as effective: when an argument is annotated as having type float, an argument of type int is acceptable; similar, for an argument annotated as having type complex, arguments of type float or int are acceptable.

(Bold emphasis mine).

Ideally you would still use numbers.Real:

from numbers import Real

def my_func(number: Real):

as that would accept fractions.Fraction() and decimal.Decimal() objects as well; the number pyramid is broader than just integers and floating point values.

However, these are not currently working when using mypy to do your type checking, see Mypy #3186.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...