Prateek wrote:
> Hi
>
> Whenever I use help(input) inside Python shell i get the following output:
>
>>>>
>>>> help(input)
> Help on built-in function input in module builtins:
>
> input(...)
> input([prompt]) -> string
>
> I want to know what the significance of "-> string". I have tried
> consulting several books but none of them gave me a clear-cut explanation
> for this.
Note that the "->" is also valid Python:
>>> def f(x: int) -> str:
... return "<{}>".format(x)
...
>>> f(42)
'<42>'
It was originally "invented" here
https://www.python.org/dev/peps/pep-3107/#return-values
and later morphed into
https://docs.python.org/dev/library/typing.html
According to that f() should take an integer and return a str. This
information can be used by type checkers like
http://mypy-lang.org/
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