sparc_spread sparc_spread - 24 days ago 9
Python Question

Writing pandas DataFrame to Excel with different formats for different columns

I am trying to write a pandas

DataFrame
to an
.xlsx
file where different numerical columns would have different formats. For example, some would show only two decimal places, some would show none, some would be formatted as percents with a "%" symbol, etc.

I noticed that
DataFrame.to_html()
has a
formatters
parameter that allows one to do just that, mapping different formats to different columns. However, there is no similar parameter on the
DataFrame.to_excel()
method. The most we have is a
float_format
that is global to all numbers.

I have read many SO posts that are at least partly related to my question, for example:



Are there other more convenient Excel-related functions/properties in the pandas API that can help here, or something similar on
openpyxl
, or perhaps some way to specify output format metadata directly onto each column in the
DataFrame
that would then be interpreted downstream by different outputters?

Answer

You can do this with Pandas 0.16 and the XlsxWriter engine by accessing the underlying workbook and worksheet objects:

import pandas as pd

# Create a Pandas dataframe from some data.
df = pd.DataFrame(zip(
    [1010, 2020, 3030, 2020, 1515, 3030, 4545],
    [.1, .2, .33, .25, .5, .75, .45],
    [.1, .2, .33, .25, .5, .75, .45],
))

# Create a Pandas Excel writer using XlsxWriter as the engine.
writer = pd.ExcelWriter('test.xlsx', engine='xlsxwriter')
df.to_excel(writer, sheet_name='Sheet1')

# Get the xlsxwriter objects from the dataframe writer object.
workbook  = writer.book
worksheet = writer.sheets['Sheet1']

# Add some cell formats.
format1 = workbook.add_format({'num_format': '#,##0.00'})
format2 = workbook.add_format({'num_format': '0%'})
format3 = workbook.add_format({'num_format': 'h:mm:ss AM/PM'})

# Set the column width and format.
worksheet.set_column('B:B', 18, format1)

# Set the format but not the column width.
worksheet.set_column('C:C', None, format2)

worksheet.set_column('D:D', 16, format3)

# Close the Pandas Excel writer and output the Excel file.
writer.save()

Output:

enter image description here

See also Working with Python Pandas and XlsxWriter.

Comments