API: consider better decorator option

[chris-b1]

It's not an issue in py3.5, but in older versions this is annoying - because a decorator is used in the definition, the function signature on to_datetime is lost. This is the big one I've run into, but there may be some other places in the API it comes up.

I saw this blog today - could use one of the strategies there. It may make sense to vendor rather than adding another dependency?
https://hynek.me/articles/decorators/

[jreback]

it should propagate

I think it just needs wraps

[jreback]

actually @chris-b1 where is this from? ? in ipython and help work just fine. can you elaborate.

[jreback]

actually read that article. Ok that is nice.

[chris-b1]

I'm assuming you're looking on python3? In python 2 the standard wraps doesn't propagate signatures.

In [1]: import functools

In [2]: def dec_stdlib(f):
   ...:     @functools.wraps(f)
   ...:     def inner(*args, **kwargs):
   ...:         f(*args, **kwargs)
   ...:     return inner

In [6]: import boltons.funcutils

In [7]: def dec_boltons(f):
   ...:     @boltons.funcutils.wraps(f)
   ...:     def inner(*args, **kwargs):
   ...:         f(*args, **kwargs)
   ...:     return inner

In [4]: @dec_stdlib
   ...: def f(a, b):
   ...:     return a + b

In [5]: f?
Signature: f(*args, **kwargs)
Docstring: <no docstring>
Type:      function


In [8]: @dec_boltons
   ...: def f(a, b):
   ...:     return a + b

In [9]: f?
Signature: f(a, b)
Type:      function

[chris-b1]

I attempted this using https://github.com/mahmoud/boltons/blob/master/boltons/funcutils.py - which has a wraps replacement, but the interaction of the magic broke a bunch of stuff. I'm sure it would be possible to work through it, but I'm letting this one sit - I guess it's good self-motivation to update things to python 3.