Missing support to non-interactive STDIN (only 1 input string)

[espositocloud]

It can be useful providing a string to stdin, in particular with Subprocess.

[penguinolog]

Propose interface
stdin: typing.Optional[typing.Union[str, typing.Iterable[str]]] = None
An input should be under global timeout conditions due to possible pauses on source side

[espositocloud]

What about stdin: typing.Optional[str] instead?

[penguinolog]

Than we will not support complex situations, but as 1 step looks good: minimal functionality will work good and no timeout required