I'm trying to export a multi index pandas dataframe to Excel with the row indexes and column labels intact. I also want the "Pool" index rows in the first column to be merged, which I believe pd.to_excel is supposed to do.
I've tried openpyxl as well, but cannot seem to get this to work without the ValueError. I also tried df=df.reset_index() just to see if I could get a flat file showing all the index and column labels, and that didn't work. Below is the code and results:
Python 3.6.0 (v3.6.0:41df79263a11, Dec 22 2016, 17:23:13)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pandas as pd
>>> import numpy as np
>>> import math
>>> s1arrays = [np.array(['Pool1', 'Pool1', 'Pool2', 'Pool2']),
... np.array(['Rate1', 'Rate2', 'Rate1', 'Rate2'])]
>>> tuples = list(zip(*s1arrays))
>>> index = pd.MultiIndex.from_tuples(tuples, names=['Pool', 'Rate'])
>>> df = pd.DataFrame(np.random.randn(4, 3), columns=[2019, 2020, 2021], index=index)
>>> print(df)
2019 2020 2021
Pool Rate
Pool1 Rate1 0.564911 -0.883633 -0.333450
Rate2 -1.043308 1.543050 1.342350
Pool2 Rate1 -0.838110 2.287242 -1.285863
Rate2 0.076783 -1.074720 0.801417
>>> df.to_excel('Test Output.xlsx', sheet_name='Sheet1')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/core/generic.py", line 2127, in to_excel
engine=engine)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/io/formats/excel.py", line 662, in write
freeze_panes=freeze_panes)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/io/excel.py", line 1605, in write_cells
xcell.value, fmt = self._value_with_fmt(cell.val)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/openpyxl/cell/cell.py", line 252, in value
self._bind_value(value)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/openpyxl/cell/cell.py", line 218, in _bind_value
raise ValueError("Cannot convert {0!r} to Excel".format(value))
ValueError: Cannot convert 'Pool1' to Excel
What is the meaning of "Cannot convert {0!r} to Excel".format(value)) in this context?
Problem is in old version of pandas, for me it working nice in last version:
pandas 0.24.2
openpyxl: 2.4.10
xlrd: 1.1.0
xlwt: 1.3.0
xlsxwriter: 1.0.2
So please upgrade your pandas version.