Manipulate Excel from Python - python

I would like to manipulate an Excel spreadsheet from Python, e.g. open it, and execute an embedded VBA macro, or some set of actions on the data inside. I have a choice of whether I would like to work on Windows or Linux for this.
There are packages ways to do this (xlwings package from this answer) but I am looking for something more native to explore what options are there.
I think one way to do this is the COM interface on Windows, which xlwings itself wraps. I found win32com python module, but seem to have very little documentation on manipulating particular objects, and what methods and attributes are available. Can someone please point me to a good information source (books are also ok)?
Alternatively, are there other options to do this, and if so, where can I read up on them?

I have gotten around this by using the Auto_Open() function in VBA, which runs when the Excel file opens.
Public Sub Auto_Open()
''' Run other macro here
End Sub
You could then open the Excel file using subprocess.popen. This is a bit of a hack, but avoids using win32com. I had to take this route because win32com wouldn't work on our locked down computers.

Related

How to automate excel tasks efficiently with xlwings and python?

I know that xlwings uses windows COM and stuffs, and based on this: https://support.microsoft.com/en-us/help/196776/office-automation-using-visual-c (8th Question):
A common cause of speed problems with Automation is with repetitive reading and writing of data. This is typical for Excel Automation clients.
And that's exactly what I am doing, tons of reading and writing, and later on I can see that EXCEL.exe is taking up 50% of my CPU usage and my python script has kind of stopped (it just halts there, but python.exe is still on TM).
Now is there anyway to work with this? I asked because, continuing the quote above, Microsoft says:
However, most people aren't aware that this data can usually be written or read all at once using SAFEARRAY.
So I guess there's a way to work like this on python using xlwings?
Please be noted that: there are things I cant do on other libraries, like "Getting the values on the cells which are visible to the user, all I get is formulas". So I guess xlwings is that way to go. Thanks.

Maya Python creating a script with a script

I've got a kind of weird question--but would be immensely useful if it is possible--in Maya using Python, can I take in several points of user input and have Python create a separate script for me? In this instance, I want to take in controller and locator names and have Python spit out a complete IKFK match script also in Python (it's really just a lot of getAttr and setAttr commands, although with 6 if statements per limb for PV matching.) The only other wrinkle there is that it has to be able to prefix hierarchy names in the script if necessary if the rig is imported into a new scene rather than just opened. There's an expression component to my switches that it would be nice if Python could make for me, too.
Is this possible or am I crazy?
That's no problem. Just write a textfile with a .py extension into a path where maya can find it. Then you have to import it somewhere. Creating expressions is not a problem either.
Maybe it could make sense to think about the approach you choose. Imagine you have written a dozen of these new python files and you discover a problem in the script, you will have to redo it. I'd try to collect all data and only write the required informations into a textfile e.g. in json format. Then you can read the data and rebuild your skeletons.

Do I need to have Excel installed to use Openpyxl "interactively"? Can it interact with .ODS format?

I have currently written a Python script that uses UNO to interact with a LibreOffice .ods document. However, it is very unstable and is causing a lot of system errors and crashing on Ubuntu 17.04.
I read through the openpyxl docs but I can't find the answer to this quick question: Can I use openpyxl on Ubuntu to dynamically manipulate a .XLSX or a .ODS document with embedded formulas?
I.e. I want to open the document, read data from the cells, update the cell values in a loop, read the new output data from the document's own formulas, and then load this output into a numpy array and close the document without saving it.
Does Excel/libreoffice have to be installed for openpyxl to use the embedded formulas in this way?
Thank you
OpenPyXL doesn't need and cannot use a running instance of Excel. It doesn't interact with .ods at all. The closest thing to OpenPyXL for .ods is pyexcel-ods. The only practical way to evaluate Excel formulas is with a running instance of Excel. Likewise, the only practical way to evaluate LibreOffice formulas is with a running instance of LibreOffice.
So if you want to use OpenPyXL or pyexcel-ods "interactively", you would have to not use Excel/LibreOffice formulas but instead do all the calculations with Python.
If you need the formulas and you need to run it in Linux, then using UNO in some form (to control a running instance of LibreOffice) is probably still your best bet. Note that there are a few different Python interfaces to UNO, such as PyOO and UnoTools. I don't know what you're using now.
Finally, if the UNO-based methods are really too unstable, and you do have access to Excel, then you could try xlwings. It would be fairly convoluted to get this to run in Linux (it might require a virtual machine; testimonials for Excel under Wine have been mixed at best).

How to open Excel instance in python on MAC?

I think this question has been asked before but it's not clear, in the original question the user has provided excel.exe which is a windows executable extension and not for mac.
I need to open new Excel instance in Python on MAC.
which module should I import?
I'm a newbie I have completed learning python language, but have trouble understanding documentation.
If all you need to do is launch Excel, the best way to do it is to use LaunchServices to do it.
If you have PyObjC (which you do if you're using the Python that Apple pre-installs on 10.6 and later; otherwise, you may have to install it):
import Foundation
ws = Foundation.NSWorkspace.sharedWorkspace()
ws.launchApplication_('Microsoft Excel')
If not, you can always use the open tool:
import subprocess
subprocess.check_call(['open', '-a', 'Microsoft Excel'])
Either way, you're effectively launching Excel the same way as if the user double-clicked the app icon in Finder.
If you want to make Excel do something simple like open a specific document, that's not much harder. Look at the NSWorkspace or open documentation to see how to do whatever you want.
If you actually want to control Excel—e.g., open a document, make some changes, and save it—you'll want to use its AppleScript interface.
Apple's recommended way of doing that is via ScriptingBridge, or using a dual-language approach (write AppleScripts and execute them via NSAppleScript—which, in Python, you do through PyObjC). However, I'd probably use appscript (get the code from here). Despite the fact that it's been abandoned by its original creator, and is only being sparsely maintained, and will probably eventually stop working with some future OS X version, it's still much better than the official solutions.
Here's a sample (untested, because I don't have Excel here):
import appscript
excel = appscript.app('Microsoft Excel')
excel.workbooks[1].column[2].row[2].formula.set('=A2+1')
From the comments it is not completely clear if you need to 'update' an Excel file with data, and just assume that you need Excel to do so, or that you need to change some excel files to include new data.
It is usually much easier, and certainly faster (wrt excution speed) to go with 'updating' an Excel file without starting Excel. However updating is not the right word: you have to read in the file and write it out new. You can of course overwrite the orginal file, so it looks like an update.
For 'updating' you can use the trio xlrd, xlwt, xlutils if the files you work with are .xls files (Excel 2003). IIRC xlwt does not support .xlsx for writing (but xlrd can read those files).
For .xlsx files I use openpyxl,
Both are good enough for writing things like data, formula and basic formatting.
If you have existing Excel files which you use as 'templates' with information that would get lost if you read/write using one of the above packages, then you have to go with updating the file in Excel. I had to do so because I had no easy way to include Visual Basic macros and very specific formatting specified by a client. And sometimes it is just easier to visually setup a spreadsheet and then just fill the cells programmatically. But this was all done on Windows.
If you really have to drive Excel on Mac, because you need to use existing files as templates, I suggest you look at Applescript. Or, if it is an option, look at OpenOffice/LibreOffice PyUno interface.

Creating excel chart from text file

I am running a simulation that saves some result in a file from which I take the data I need and save it in
result.dat
like so:
SAN.statisticsCollector.Network Response Time
Min: 0.210169
Max: 8781.55
average: 346.966666667
I do all this using python, and it was easy to convert result.dat into an excel file using xlwt. The problem is that creating charts using xlwt is not possible. I than came across Jpype, but installation on my ubuntu 12.04 machine was a headache. I'm probably just being lazy but still - is there any other way, not necessarily python-related, to convert result.dat into an excel file with charts?
Thanks
P.s the file I want to create is a spreadsheet, not Microsoft's Excel!
there is a now a new possibility: http://pythonhosted.org/openpyxl/charts.html
and http://xlsxwriter.readthedocs.org/chart.html
The main problem is that currently there's no Python library that implements MS Excel chart creation, and, obviously, they will not appear due to lack of good chart format documentation (as python-excel.org guys told) and its huge complecity.
There are two other options though:
Another option is to use 3-rd party tools (like JPype that you've mentioned) combining them with Python scripts. As far as I know, except Java smartXML there's no libraries that are capable of creating excel charts (or course, there are ones for .NET, e.g. expertXLS) and I'm not sure it will run on Mono + IronPython, though you can try.
The third option is Win32 COM API, e.g. like described in this SO post, which is not quite an option for you due to your working operating system.

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