This is an idea which has been brought up before, sometimes introduced
as "heresy". But an interesting twist has surfaced now which is
typing.
But firstly, let me present the idea. It is very simple, that Python
should have declarative imports, usable anywhere using a simple
syntax, @<dotted-name>.
For example, `some_regex = @re.compile(...)`.
What happens then is that before anything else in that module, that
symbol is imported:
from re import compile as _mangled_re_compile
It must be the very first thing (hoisting) because when else would it
happen? It's been suggested before to have a shorthand syntax which
does a dynamic import at the time of using it but this brings me to
the twist:
We want typing to pick up these imports. And this twist has a second
leg which is that we often need to import symbols simply in order to
type some argument type or return type. This leads to a great many
more imports to type.
(Nevermind that if you want to take typing further, abstract
interfaces really make more sense rather than specific
implementations, but the point is the same.)
A situation where this would come in really handy is in scripting such
as how we use Python in Apache Airflow to let users write out simple
workflows. A workflow definition which could be a 5-liner quickly
becomes a 20-liner – consider for example:
default_args = {
"start_date": @datetime.datetime(...)
}
It's a lot more ergonomic from a user perspective (well perhaps for
some users and for some programs).
Thoughts?
Cheers
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as "heresy". But an interesting twist has surfaced now which is
typing.
But firstly, let me present the idea. It is very simple, that Python
should have declarative imports, usable anywhere using a simple
syntax, @<dotted-name>.
For example, `some_regex = @re.compile(...)`.
What happens then is that before anything else in that module, that
symbol is imported:
from re import compile as _mangled_re_compile
It must be the very first thing (hoisting) because when else would it
happen? It's been suggested before to have a shorthand syntax which
does a dynamic import at the time of using it but this brings me to
the twist:
We want typing to pick up these imports. And this twist has a second
leg which is that we often need to import symbols simply in order to
type some argument type or return type. This leads to a great many
more imports to type.
(Nevermind that if you want to take typing further, abstract
interfaces really make more sense rather than specific
implementations, but the point is the same.)
A situation where this would come in really handy is in scripting such
as how we use Python in Apache Airflow to let users write out simple
workflows. A workflow definition which could be a 5-liner quickly
becomes a 20-liner – consider for example:
default_args = {
"start_date": @datetime.datetime(...)
}
It's a lot more ergonomic from a user perspective (well perhaps for
some users and for some programs).
Thoughts?
Cheers
_______________________________________________
Python-Dev mailing list -- python-dev@python.org
To unsubscribe send an email to python-dev-leave@python.org
https://mail.python.org/mailman3/lists/python-dev.python.org/
Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/UX6EJHLJNNLMFPWVPF5ANYHQSHDZK7SV/
Code of Conduct: http://python.org/psf/codeofconduct/
