BUG: ensure Series.name is hashable, #12610

[chinskiy]

• closes Bug: Pandas Series name attribute can be array #12610
• tests added / passed
• passes git diff upstream/master | flake8 --diff

pandas >= 0.18.0 will no longer support compatibility with Python version 2.6 and since Python 2.6 we can use the abstract base class collections.Hashable.

[jreback]

we already have an pandas.core.common.is_hashable just use this

[jreback]

but this needs to be checked more generally (higher up in the constructor)

prob need a few more tests

[chinskiy]

ok.

[jreback]

no reason to close
just update push again

[jreback]

actually I realize that the ref issue #9193 was not merged.

can you rebase/update this. Then add the .name attribute like was one there?

(this covers setting as well).

further for the actual tests

lets test both the constructor and setting with:

• a bunch of invalid things (you did some already: dict, np.array, list)
• a bunch of valid things (int, float, string, datetime, tuple)

[chinskiy]

Okay, I will try to do this soon.
Additional test - not problem.

add .name atribute - you mean about:

@property
def name(self):
    return self._name

@name.setter
def name(self, value):
    if is_hashable(value):

P.S. Not a topic of this conversation: yesterday I add to wiki translation about Pandas on Ukrainian https://uk.wikipedia.org/wiki/Pandas - think it's useful.

[jreback]

Yes, if you take pretty that other PR and incorporate would be great. You can prob remove the explicit check in the constructor as it will use .name to set the name as well (where all of the checking should actually happen).

Thanks for the wiki update! cool!

[jreback]

@name.setter
def name(self, value):
    if value is not None and not com.is_hashable(value):
        raise .......
    object.__setattr__(self, '_name', None)

[chinskiy]

Ok, but how better add object.__setattr__(self, '_name', value) to this code?
object.__setattr__(self, '_name', None) only if name attribute not added.

[jreback]

name should NEVER be defined, only _name

[jreback]

That's why the pickling tests are important. I think this should work (as old pickles have a .name instance variable); we are now converting it when set to a ._name, but should be transparent to the user.

[jreback]

I think you might need to change: https://github.com/pydata/pandas/blob/master/pandas/core/series.py#L235 as well (and look and see if anywhere else is doing something similar)

[chinskiy]

Not sure that correctly understood here and with _name below

[jreback]

you are duplicating code here.

just self.name = name (this will then hit the setattr property)

[jreback]

that's all I meant was to change it to a more 'normal' setter

[chinskiy]

sorry, my fault, don't understand. I'm just studying, will make it as it must be.

[jreback]

just put this higher up, in the existing space, so you aren't adding lines

[jreback]

thanks @chinskiy keep em coming!