DataFrame.unstack(label) accepts wrong labels if index is flat · Issue #18303 · pandas-dev/pandas (original) (raw)

Code Sample, a copy-pastable example if possible

In [2]: df = pd.DataFrame(index=range(2), columns=pd.MultiIndex.from_product([range(2), range(2)]))

In [3]: df.unstack('mistake') Out[3]: 0 0 0 NaN 1 NaN 1 0 NaN 1 NaN 1 0 0 NaN 1 NaN 1 0 NaN 1 NaN dtype: object

Problem description

An error should be raised.

Expected Output

KeyError

Output of pd.show_versions()

In [4]: pd.show_versions()

INSTALLED VERSIONS

commit: 63e8527
python: 3.5.3.final.0
python-bits: 64
OS: Linux
OS-release: 4.9.0-3-amd64
machine: x86_64
processor:
byteorder: little
LC_ALL: None
LANG: it_IT.UTF-8
LOCALE: it_IT.UTF-8

pandas: 0.22.0.dev0+131.g63e8527d3
pytest: 3.2.3
pip: 9.0.1
setuptools: 36.7.0
Cython: 0.25.2
numpy: 1.12.1
scipy: 0.19.0
pyarrow: None
xarray: None
IPython: 6.2.1
sphinx: 1.5.6
patsy: 0.4.1
dateutil: 2.6.1
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: None
xlrd: 1.0.0
xlwt: 1.1.2
xlsxwriter: 0.9.6
lxml: None
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