From jorisvandenbossche at gmail.com  Mon Oct  1 06:17:12 2018
From: jorisvandenbossche at gmail.com (Joris Van den Bossche)
Date: Mon, 1 Oct 2018 12:17:12 +0200
Subject: [Pandas-dev] Pandas loc function including upper limit
In-Reply-To: <CACncA5Ki9B_1vm5v38pk6Gh9j=ob1ORstYhWiof469KRZ8k1Ow@mail.gmail.com>
References: <CACncA5Ki9B_1vm5v38pk6Gh9j=ob1ORstYhWiof469KRZ8k1Ow@mail.gmail.com>
Message-ID: <CALQtMBb+LhphZ1gEPN-Xjgt6R8j7xyfLq2wVwNs6KVLL_yuBRw@mail.gmail.com>

Hi Hritik,

You can question the logic of this, but this is such a ingrained /
fundamental functionality of pandas, that I don't think this is something
that we can change (even if we would like to).

But it is true this can be counter intuitive / confusing if you are used to
how integer positional indexing works in python / numpy / iloc. This is
certainly one of the "gotcha's" in pandas indexing where we differentiate
between label-based and positional indexing, that you need to be aware of.

That said, I personally think there is also some logic in including the
last value for label-based indexing. For example, when having not a simple
range of integers as index, the values are often irregular and given a
specific label, you don't necessarily know what the value is just before
that label. So it might be more predictable the if the passed label (the
upper limit) is included.

Best,
Joris


Op zo 30 sep. 2018 om 10:02 schreef Hritik Vijay <hritikxx8 at gmail.com>:

> The `loc` function includes the upper limit which is very counter
> intuitive.
> Shouldn't it follow iloc and other indexing methods and exclude upper
> limit (at least for integral slices)
>
> --
> Regards
> Hritik Vijay
> _______________________________________________
> Pandas-dev mailing list
> Pandas-dev at python.org
> https://mail.python.org/mailman/listinfo/pandas-dev
>
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From shoyer at gmail.com  Mon Oct  1 09:51:10 2018
From: shoyer at gmail.com (Stephan Hoyer)
Date: Mon, 1 Oct 2018 15:51:10 +0200
Subject: [Pandas-dev] Pandas loc function including upper limit
In-Reply-To: <CALQtMBb+LhphZ1gEPN-Xjgt6R8j7xyfLq2wVwNs6KVLL_yuBRw@mail.gmail.com>
References: <CACncA5Ki9B_1vm5v38pk6Gh9j=ob1ORstYhWiof469KRZ8k1Ow@mail.gmail.com>
 <CALQtMBb+LhphZ1gEPN-Xjgt6R8j7xyfLq2wVwNs6KVLL_yuBRw@mail.gmail.com>
Message-ID: <CAEQ_TvdV3Eq4EsLwyt7YyA2YNCaHWEAz+Ljq6W2mek8d=fkmUQ@mail.gmail.com>

This has been reported a number of times as unintuive by xarray users as
well (xarray uses pandas internally for the label based slicing).

I agree that there is some logic to including the last value, since at
least for some datatypes (e.g., cateogical) isn't always obvious what the
next value will be.

I do tend to think this was a mistake, because it means you can't break up
an object into non-overlapping but contiguous slices with only a single
list of "dividing" indexes. It's particularly awkward with general
numeric/float indexes, where calculating the next float is not obvious --
it would be nice if .loc[0:10] and .loc[10:20] did not both include the
value 10. Datetime indexes would also be pretty as awkward if pandas did
not have the shortcut where omitted times in the end of a slice are taken
to be the last value.

That said, it does feel rather late to change this behavior. I don't see
anyway to do a graceful deprecation cycle for this without a new indexing
attribute.

On Mon, Oct 1, 2018 at 12:17 PM Joris Van den Bossche <
jorisvandenbossche at gmail.com> wrote:

> Hi Hritik,
>
> You can question the logic of this, but this is such a ingrained /
> fundamental functionality of pandas, that I don't think this is something
> that we can change (even if we would like to).
>
> But it is true this can be counter intuitive / confusing if you are used
> to how integer positional indexing works in python / numpy / iloc. This is
> certainly one of the "gotcha's" in pandas indexing where we differentiate
> between label-based and positional indexing, that you need to be aware of.
>
> That said, I personally think there is also some logic in including the
> last value for label-based indexing. For example, when having not a simple
> range of integers as index, the values are often irregular and given a
> specific label, you don't necessarily know what the value is just before
> that label. So it might be more predictable the if the passed label (the
> upper limit) is included.
>
> Best,
> Joris
>
>
> Op zo 30 sep. 2018 om 10:02 schreef Hritik Vijay <hritikxx8 at gmail.com>:
>
>> The `loc` function includes the upper limit which is very counter
>> intuitive.
>> Shouldn't it follow iloc and other indexing methods and exclude upper
>> limit (at least for integral slices)
>>
>> --
>> Regards
>> Hritik Vijay
>> _______________________________________________
>> Pandas-dev mailing list
>> Pandas-dev at python.org
>> https://mail.python.org/mailman/listinfo/pandas-dev
>>
> _______________________________________________
> Pandas-dev mailing list
> Pandas-dev at python.org
> https://mail.python.org/mailman/listinfo/pandas-dev
>
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From garcia.marc at gmail.com  Mon Oct  1 14:45:02 2018
From: garcia.marc at gmail.com (Marc Garcia)
Date: Mon, 1 Oct 2018 19:45:02 +0100
Subject: [Pandas-dev] Hacktoberfest
Message-ID: <CAEk5N5teqpVoF+wsNh_aL2SiB1zWx8pJRebirRhzDJv6f_FBaw@mail.gmail.com>

Seems like during this month people get a free t-shirt for sending 5 PR (
https://hacktoberfest.digitalocean.com).

Is it ok if I close PRs like this as spam:
https://github.com/pandas-dev/pandas/pull/22925

You'll know better from last years, but I guess we'll receive many of them.
Is it ok if I edit the template with a message too?
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From gfyoung17 at gmail.com  Mon Oct  1 15:27:50 2018
From: gfyoung17 at gmail.com (G Young)
Date: Mon, 1 Oct 2018 12:27:50 -0700
Subject: [Pandas-dev] Hacktoberfest
In-Reply-To: <CAEk5N5teqpVoF+wsNh_aL2SiB1zWx8pJRebirRhzDJv6f_FBaw@mail.gmail.com>
References: <CAEk5N5teqpVoF+wsNh_aL2SiB1zWx8pJRebirRhzDJv6f_FBaw@mail.gmail.com>
Message-ID: <CAJ1_J5iAbfH2oCfJQBvRjKtpa0TDr=hN27t_F6HK2utx+bnC1Q@mail.gmail.com>

Probably can close it.  To be fair, maybe they got confused by the
instructions on the website ?:

[image: Screen Shot 2018-10-01 at 12.26.16 PM.png]


On Mon, Oct 1, 2018 at 11:45 AM Marc Garcia <garcia.marc at gmail.com> wrote:

> Seems like during this month people get a free t-shirt for sending 5 PR (
> https://hacktoberfest.digitalocean.com).
>
> Is it ok if I close PRs like this as spam:
> https://github.com/pandas-dev/pandas/pull/22925
>
> You'll know better from last years, but I guess we'll receive many of
> them. Is it ok if I edit the template with a message too?
> _______________________________________________
> Pandas-dev mailing list
> Pandas-dev at python.org
> https://mail.python.org/mailman/listinfo/pandas-dev
>
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