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multiindex column in to_excel

See original GitHub issue

link to #1651

Saving a multiindex column to_excel saves a sparse index.

Migrated from this StackOverflow question, with a smaller DataFrame.

In [1]: m = MultiIndex.from_tuples([(1,1),(1,2)], names=['a','b'])

In [2]: df = DataFrame([[1,2],[3,4]], columns=m)

In [3]: df
Out[3]: 
a  1   
b  1  2
0  1  2
1  3  4

In [4]: df.to_excel('test.xls')

Saves the xls:

    1.1 .2
0   1   2
1   3   4

This differs from how to_csv (which is not sparse):

,"(1L, 1L)","(1L, 2L)"
0,1,2
1,3,4

Issue Analytics

State:
Created 11 years ago
Comments:18 (5 by maintainers)

Top GitHub Comments

5reactions

ronanpaixaocommented, Oct 25, 2017

@jreback Can this be reopened? I also get this problem.

I’ve commented this on #6618, which seems related. From what I can see, the problem is that pandas is reserving the first column of the header rows to the MultiIndex, and creates a new line for the row index name even if it is unnamed:

>>> df = pd.DataFrame([[1,2,3],[4,5,6]], columns=pd.MultiIndex.from_tuples([('A'
,''),('B','C'),('B','D')]))
>>> df.to_excel("out.xlsx", index_label="Foo")

pandas_to_excel_bug2

This bug was fixed some time ago for simple columns, but it was probably not a very good solution, since it is still buggy for MultiIndex columns:

>>> df = pd.DataFrame([[1,2,3],[4,5,6]], columns=['A','B','C'])
>>> df.to_excel("out.xlsx", index_label="Foo")

pandas_to_excel_bug3

Version information:

>>> pd.show_versions()

INSTALLED VERSIONS
------------------
commit: None
python: 3.6.1.final.0
python-bits: 32
OS: Windows
OS-release: 7
machine: AMD64
processor: Intel64 Family 6 Model 42 Stepping 7, GenuineIntel
byteorder: little
LC_ALL: None
LANG: None
LOCALE: None.None

pandas: 0.20.1
pytest: 3.0.7
pip: 9.0.1
setuptools: 27.2.0
Cython: 0.25.2
numpy: 1.12.1
scipy: 0.19.0
xarray: None
IPython: 5.3.0
sphinx: 1.5.6
patsy: 0.4.1
dateutil: 2.6.0
pytz: 2017.2
blosc: None
bottleneck: 1.2.1
tables: 3.2.2
numexpr: 2.6.2
feather: None
matplotlib: 2.0.2
openpyxl: 2.4.7
xlrd: 1.0.0
xlwt: 1.2.0
xlsxwriter: 0.9.6
lxml: 3.7.3
bs4: 4.6.0
html5lib: 0.999
sqlalchemy: 1.1.9
pymysql: None
psycopg2: None
jinja2: 2.9.6
s3fs: None
pandas_gbq: None
pandas_datareader: None

3reactions

jd901215commented, Jul 18, 2017

@mappingvermont I’m getting the same result with a real example. I think it is a bug. Using latest version pandas 0.19.2