[Tutor] Interoperating with Excel, was Re: Questions

[Albert-Jan Roskam]

On 7 Apr 2019 14:07, Peter Otten <__peter__ at web.de> wrote:

Diana Katz wrote:

> 1) Can you use python from excel? Or just export to excel?
> 2) I am trying to see if there's a way using python to automate all of
> this work that I need to do. I have to collect quarterly segment data for
> hundreds of public companies and go back at least 12-16 quarters. We use
> an aggregator like factset and they actually don't have this option
> available in an automated way. So I'm trying to see if there's a way to
> build this. Basically, I get my data from sec.gov and they have
> interactive data - they even have the data in excel (though it's a messy
> file and hard to read). I attached some of the steps and the data that i'd
> want to see. Basically i'd want the excel to look like:
> old to new quarters - going back 12 to 16 quarters (more if possible but
> not if it will stop the project).
>  Columns: 3/31/2017, 6/30/2017, 9/30/17, 12/31/17, 3/313/2018...
> Rows:
> Sales for segment A
> Sales for Segment b
> Sales for SEgment C
> …(for as many segments as they have)
>
> Earnings for Segment A
> .Earnings for Segment B
>
> Depreciation for Segment A
> Depreciation for Segment B
> Depreciation for Segment C...

These look like "pivot tables" which are well supported by Excel.
I expect that this is easy to automate with a little bit of Basic.

Of course you can build these tables with a Python script if you feel more
comfortable in Python. Then either write them into csv files ("comma
separated value", supported by the standard library)

https://docs.python.org/3/library/csv.html

which can be read by Excel -- or use a dedicated library. Google came up
with

https://xlsxwriter.readthedocs.io/


===>> There's xlrd for xls files, openpyxl for xlsx files. And pandas can also read excel, and you can use groupby, pivottable etc. there:
https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_excel.html. With the win32com library you can also automate Excel (Windows only).

Excel is evil, especially if the files are made by humans and come from different sources.