ENH: name(s) argument for reset_index?

[jorisvandenbossche]

An idea: to be able to specify the a name when resetting the index, which would override the index name or the default value when index name is None.

Eg something like this:

In [10]: df = pd.DataFrame(np.random.rand(4,3), columns=list('ABC'), index=pd.date_range('2013-01-01', periods=4))
In [11]: df
Out[11]: 
                   A         B         C
2013-01-01  0.313664  0.606445  0.048081
2013-01-02  0.907785  0.004429  0.374456
2013-01-03  0.916584  0.067639  0.467712
2013-01-04  0.712824  0.687895  0.397960

In [12]: df.reset_index()
Out[12]: 
       index         A         B         C
0 2013-01-01  0.313664  0.606445  0.048081
1 2013-01-02  0.907785  0.004429  0.374456
2 2013-01-03  0.916584  0.067639  0.467712
3 2013-01-04  0.712824  0.687895  0.397960

In [12]: df.reset_index(name='datetime')
Out[12]: 
    datetime         A         B         C
0 2013-01-01  0.313664  0.606445  0.048081
1 2013-01-02  0.907785  0.004429  0.374456
2 2013-01-03  0.916584  0.067639  0.467712
3 2013-01-04  0.712824  0.687895  0.397960

For multi-index, you should provide a list.

[jreback]

you can do

df = df.copy()
df.index = df.index.set_names([...])
df.reset_index()

so this is a convience yes?

[jorisvandenbossche]

yes, as a convenience I think (and like this it would do a copy less, only the copy inside reset_index?)

[jreback]

Series already has this do just a extending to df yes?

sounds good

[jorisvandenbossche]

Ah, I didn't know Series.reset_index already had something like this. Would certainly be a reason to get that aligned.

Only problems is that it is different there, as it specifies the name for the Series values, not for the index ..

In [19]: s = df['A']
In [20]: s.reset_index()
Out[20]: 
       index         A
0 2013-01-01  0.313664
1 2013-01-02  0.907785
2 2013-01-03  0.916584
3 2013-01-04  0.712824

In [21]: s.reset_index(name='other name')
Out[21]: 
       index  other name
0 2013-01-01    0.313664
1 2013-01-02    0.907785
2 2013-01-03    0.916584
3 2013-01-04    0.712824

[cpcloud]

index name kwarg?

[cancan101]

This also partially solves #6181