DataFrame.reset_index deletes index, does not all for ints as level arg · Issue #16263 · pandas-dev/pandas (original) (raw)
Code Sample, a copy-pastable example if possible
import pandas as pd import numpy as np pd.version
u'0.20.1'
data = pd.DataFrame(np.random.randn(4,4), columns=['A', 'B', 'C', 'D']) data
| A | B | C | D | |
|---|---|---|---|---|
| 0 | -0.134549 | 2.352525 | 0.481132 | -1.919506 |
| 1 | 1.980074 | 0.720437 | 0.410702 | -0.703470 |
| 2 | -3.063166 | -0.781255 | 0.270469 | -0.539081 |
| 3 | -1.125265 | 0.308374 | -0.166085 | -1.253959 |
data.set_index(['A'], inplace=True) data
| B | C | D | |
|---|---|---|---|
| A | |||
| -0.134549 | 2.352525 | 0.481132 | -1.919506 |
| 1.980074 | 0.720437 | 0.410702 | -0.703470 |
| -3.063166 | -0.781255 | 0.270469 | -0.539081 |
| -1.125265 | 0.308374 | -0.166085 | -1.253959 |
data.reset_index(level=['A'], inplace=True) data
| B | C | D | |
|---|---|---|---|
| 0 | 2.352525 | 0.481132 | -1.919506 |
| 1 | 0.720437 | 0.410702 | -0.703470 |
| 2 | -0.781255 | 0.270469 | -0.539081 |
| 3 | 0.308374 | -0.166085 | -1.253959 |
Problem description
between v0.19.2 and v0.20.1, the behavior of DataFrame.reset_index changed.
With a single set index:
- It does not attempt to keep the column (essentially making drop=True always on)
- level=int no longer works (iterables work)
Expected Output
v0.19.2 results:
data.reset_index(level=['A'], inplace=True) data
| A | B | C | D | |
|---|---|---|---|---|
| 0 | 0.100442 | -0.620740 | -2.018020 | 1.059871 |
| 1 | -0.530272 | 0.402598 | -1.453445 | -0.729623 |
| 2 | -1.040126 | -0.536687 | -1.136123 | -0.748891 |
| 3 | -0.269727 | 0.182250 | 0.847344 | 0.785692 |
Output of pd.show_versions()
import pandas as pd import numpy as np pd.show_versions()
INSTALLED VERSIONS
------------------
commit: None
python: 2.7.13.final.0
python-bits: 64
OS: Darwin
OS-release: 15.6.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8
LOCALE: None.None
pandas: 0.19.2
nose: None
pip: 9.0.1
setuptools: 35.0.2
Cython: None
numpy: 1.12.1
scipy: None
statsmodels: None
xarray: None
IPython: 5.3.0
sphinx: None
patsy: None
dateutil: 2.6.0
pytz: 2017.2
blosc: None
bottleneck: None
tables: None
numexpr: None
matplotlib: None
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml: None
bs4: None
html5lib: 0.999999999
httplib2: None
apiclient: None
sqlalchemy: None
pymysql: None
psycopg2: None
jinja2: 2.9.6
boto: None
pandas_datareader: None