Series.reset_index(level_name, drop=True) accepts invalid name when index is flat

Code Sample, a copy-pastable example if possible

In [2]: s = pd.Series(range(4))

In [3]: s.reset_index('wrong', drop=True)
Out[3]: 
0    0
1    1
2    2
3    3
dtype: int64

In [4]: s.reset_index('wrong')
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-4-a7b872dfe0cf> in <module>()
----> 1 s.reset_index('wrong')

~/nobackup/repo/pandas/pandas/core/series.py in reset_index(self, level, drop, name, inplace)
   1215         else:
   1216             df = self.to_frame(name)
-> 1217             return df.reset_index(level=level, drop=drop)
   1218 
   1219     def __unicode__(self):

~/nobackup/repo/pandas/pandas/core/frame.py in reset_index(self, level, drop, inplace, col_level, col_fill)
   4098             if not isinstance(level, (tuple, list)):
   4099                 level = [level]
-> 4100             level = [self.index._get_level_number(lev) for lev in level]
   4101             if isinstance(self.index, MultiIndex):
   4102                 if len(level) < self.index.nlevels:

~/nobackup/repo/pandas/pandas/core/frame.py in <listcomp>(.0)
   4098             if not isinstance(level, (tuple, list)):
   4099                 level = [level]
-> 4100             level = [self.index._get_level_number(lev) for lev in level]
   4101             if isinstance(self.index, MultiIndex):
   4102                 if len(level) < self.index.nlevels:

~/nobackup/repo/pandas/pandas/core/indexes/base.py in _get_level_number(self, level)
   1944 
   1945     def _get_level_number(self, level):
-> 1946         self._validate_index_level(level)
   1947         return 0
   1948 

~/nobackup/repo/pandas/pandas/core/indexes/base.py in _validate_index_level(self, level)
   1941         elif level != self.name:
   1942             raise KeyError('Level %s must be same as name (%s)' %
-> 1943                            (level, self.name))
   1944 
   1945     def _get_level_number(self, level):

KeyError: 'Level wrong must be same as name (None)'

In [5]: s = pd.Series(range(4), index=pd.MultiIndex.from_product([[1, 2]]*2))

In [6]: s.reset_index('wrong', drop=True)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/nobackup/repo/pandas/pandas/core/indexes/multi.py in _get_level_number(self, level)
    775                                  'level number' % level)
--> 776             level = self.names.index(level)
    777         except ValueError:

ValueError: 'wrong' is not in list

During handling of the above exception, another exception occurred:

KeyError                                  Traceback (most recent call last)
<ipython-input-6-e0d143f488d8> in <module>()
----> 1 s.reset_index('wrong', drop=True)

~/nobackup/repo/pandas/pandas/core/series.py in reset_index(self, level, drop, name, inplace)
   1199                 if not isinstance(level, (tuple, list)):
   1200                     level = [level]
-> 1201                 level = [self.index._get_level_number(lev) for lev in level]
   1202                 if len(level) < len(self.index.levels):
   1203                     new_index = self.index.droplevel(level)

~/nobackup/repo/pandas/pandas/core/series.py in <listcomp>(.0)
   1199                 if not isinstance(level, (tuple, list)):
   1200                     level = [level]
-> 1201                 level = [self.index._get_level_number(lev) for lev in level]
   1202                 if len(level) < len(self.index.levels):
   1203                     new_index = self.index.droplevel(level)

~/nobackup/repo/pandas/pandas/core/indexes/multi.py in _get_level_number(self, level)
    777         except ValueError:
    778             if not isinstance(level, int):
--> 779                 raise KeyError('Level %s not found' % str(level))
    780             elif level < 0:
    781                 level += self.nlevels

KeyError: 'Level wrong not found'

Problem description

In [3]: should raise too.

Expected Output

Same as In [4]:

Output of pd.show_versions()

INSTALLED VERSIONS

commit: None python: 3.5.3.final.0 python-bits: 64 OS: Linux OS-release: 4.9.0-6-amd64 machine: x86_64 processor: byteorder: little LC_ALL: None LANG: it_IT.UTF-8 LOCALE: it_IT.UTF-8

pandas: 0.23.0.dev0+825.ga3facfc55 pytest: 3.5.0 pip: 9.0.1 setuptools: 39.0.1 Cython: 0.25.2 numpy: 1.14.1 scipy: 0.19.0 pyarrow: None xarray: None IPython: 6.2.1 sphinx: 1.5.6 patsy: 0.5.0 dateutil: 2.7.0 pytz: 2017.2 blosc: None bottleneck: 1.2.0dev tables: 3.3.0 numexpr: 2.6.1 feather: 0.3.1 matplotlib: 2.0.0 openpyxl: 2.3.0 xlrd: 1.0.0 xlwt: 1.3.0 xlsxwriter: 0.9.6 lxml: 4.1.1 bs4: 4.5.3 html5lib: 0.999999999 sqlalchemy: 1.0.15 pymysql: None psycopg2: None jinja2: 2.10 s3fs: None fastparquet: None pandas_gbq: None pandas_datareader: 0.2.1

[toobaz]

@KalyanGokhale no official protocol (we have so many bugs we don’t typically fight over them 😉 ), and might depend on how urgent the issue is, but I guess a rule of thumb could be “always feel free to ask if the person who signed up to work on an issue is actually/still working on it, and if s/he isn’t, or doesn’t reply within a week, then feel free to steal it”. (and in general, when you start working on an issue, always mention it)

[KalyanGokhale]

@misupova sincere apologies once again.

@toobaz may be I was quick to jump on this one - but wanted to understand for future if there is any protocol you guys follow (e.g. if x # of days have passed and the person who signed up to work on an issue has not provided any update, then its fair play for someone else to pick it up etc?) - is there a middle ground between the time an issue is open and someone who has a (ready/near ready) solution can also post it…may be there is another collaborative way which I have not considered…just thinking out loud. Thanks!