Outputting A .xls File In Python - python

I have been teaching myself Python to automate some of our work processes. So far reading from Excel files (.xls, .xlsx) has gone great.
Currently I have hit a bit of a snag. Although I can output .xlsx files fine, the software system that we have to use for our primary work task can only take .xls files as an input - it cannot handle .xlsx files, and the vendor sees no reason to add .xlsx support at any point in the foreseeable future.
When I try to output a .xls file using either Pandas or OpenPyXl, and open that file in Excel, I get a warning that the file format and extension of the file do not match, which leads me to think that attempting to open this file using our software could lead to some pretty unexpected consequences (because it's actually a .xlsx file, just not named as such)
I've tried to search for how to fix this all on Google, but all I can find are guides for how to convert a .xls file to a .xlsx file (which is almost the opposite of what I need). So I was wondering if anybody could please help me on whether this can be achieved, and if it can, how.
Thank you very much for your time

Under the pandas.DataFrame.to_excel documentation you should notice a parameter called engine, which states:
engine : str, optional
Write engine to use, openpyxl or xlsxwriter. You can also set this via the options io.excel.xlsx.writer, io.excel.xls.writer, and io.excel.xlsm.writer.
What it does not state is that the engine param is automatically picked based on your file extension -- therefore, easy fix:
import pandas as pd
df = pd.DataFrame({"data": [1, 2, 3]})
df.to_excel("file.xls") # Notice desired file extension.
This will automatically use the xlwt engine, so make sure you have it installed via pip install xlwt.

Felipe is right the filename extension will set the engine parameter.
So basically all it's saying is that the old Excel format ".xls" extension is no longer supported in Pandas. So if you specify the output spreadsheet with the ".xlsx" extension the warning message disappears.

I FINALLY have the answer!
I have libreoffice installed and am using the following in the command line on windows:
"C:\Program Files\LibreOffice\program\soffice.exe" --headless --convert-to xlsx test2.xls
Currently trying to use subprocess to automate this.

Related

Embed CSV in Excel and import the data

I wrote a tool that extracts data from a large DB and outputs it to an Excel file along with (conditional) formatting to improve readability. For this I use Python with openpyxl on a Linux machine. It works great, but this package is rather slow for writing Excel.
It seems to be a lot quicker to dump the table as (compressed) csv, import that into Excel and apply formatting there using a macro/vba.
To automate the process I'd like to create an empty Excel file pre-loaded with the required VBA to do the formatting; a template. For every data dump, the data is embedded (compressed using deflate) into the Excel file and loaded into the Workbook upon opening the document (or using a "LOAD" button to circumvent macro related security things).
However, just adding some file into the Excel file raises an error when opened:
We found a problem with some content in 'Werkmap1_test_embed.xlsx'. Do you want us to try to recover as much as we can? If you trust the source of this workbook, click Yes.
Clicking Yes opens the file and shows some tracing information as XML:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<recoveryLog xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
<logFileName>Repair Result to Werkmap1_OLE_Word0.xml</logFileName>
<summary>Errors were detected in file '/Users/joostk/mnt/cluster/Werkmap1_OLE_Word.xlsx'</summary>
<additionalInfo>
<info>Excel completed file level validation and repair. Some parts of this workbook may have been repaired or discarded.</info>
</additionalInfo>
</recoveryLog>
Is it possible to avoid this? How would I embed a file into the Excel ZIP? Do I need to update some file table (which I could not file easily).
When that's done, I'd like to import the data. Can I access files in the Excel ZIP from VBA? I guess not, and I need to extract the data to some temporary path and load it from there.
I have found these helpful answers elsewhere to load ZIP and plain text:
https://stackoverflow.com/a/35781621/4998990
https://stackoverflow.com/a/11267603/4998990
Many thanks for sharing your thoughts!
so my "Answer" here is that this is caused by using Named Ranges, or an underlying table, or an embedded Query/Connection. When you start manipulating this file you will get the error that you are talking about:
There is no harm to the file if you click "yes" and open. Excel will open this in Repaired Mode which will require you to re-save the file.
The way I've worked around this is to re-read the "repaired" file, in python, and save it as another file or replace it. Essentially just do an extra step of re-reading the data into memory, and write it to a new file. The error will go away. As always, test this method before deploying to production to ensure no records are lost. The way I solve it is with two lines of pandas.
import pandas as pd
repair = pd.read_excel('PATH_TO_REPAIR_FILE')
new_file = repair.to_excel('PATH_TO_WHERE_NEW_FILE_GOES')

How to fix [Errno13] permission denied when trying to read excel file?

I tried the following code to be able to read an excel file from my personal computer.
import xlrd
book = xlrd.open_workbook('C:\\Users\eline\Documents\***\***\Python', 'Example 1.xlsx')
But I am getting the error 'Permission denied'. I am using windows and if I look at the properties of the directory and look at the 'Security' tab I have three groups/users and all three have permissions for all the authorities, except for the last option which is called 'special authorities' (as far as I know I do not need this authority to read the excel file in Python).
I have no idea how to fix this error. Furthermore, I do not have the Excel file open on my computer when running the simulation.
I really hope someone can help me to fix this error.
Sometimes, it is because you try to read the Excel file while it is opened. Close the file in Excel and you are good to go.
book = xlrd.open_workbook('C:\\Users\eline\Documents\***\***\Python', 'Example 1.xlsx')
You cannot give path like this to xlrd. path need to be single string.
If you insist you can use os module
import os
book = xlrd.open_workbook(os.path.join('C:\\Users\eline\Documents\***\***\Python', 'Example 1.xlsx'))
[Errno13] permission denied in your case is happening because you want to read folder like a file which is not allowed.
I ran into this situation also while reading an Excel file into a data frame. To me it appears that it is a Python and/or Excel bug which we should probably not hide by using os.path.join even if that solves the problem. My situation involved an excel spreadsheet that links cells to another CSV file. If this excel file is freshly opened and open when I try to read it in python, it fails.
Python reads it correctly if I do an unnecessary save of the open Excel file.

Error opening text file saved with .xls extension in python

I'm using labview to create and save data from an experiment. Labview itself creates a text file but saves it automatically with a .xls extension (word 1997-2003--it's an old setup that was never changed because it never broke). Whenever I go to open one of the data files, excel spits out this:
"The file you are trying to open, 'name.ext', is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a trusted source before opening the file. Do you want to open the file now?"
I'm generating a lot of data, so I want to use python to sort it out and do some quick analysis over files in a directory.
The problem is that python doesn't like that it's a text file saved with a .xls extension. It can cycle through the directory just fine to get the file names, but whenver I actually try to open the file or do anything with it, I get the error in the image attached. This happens if I change the extension to .xls, .xlsx, or do nothing with it at all and let it try to open the original filename.
error message
I literally have hundreds of these .xls files. I know I can go through, open each one in excel and save as a real excel file by hand, but that will take hours. Can someone please help me figure a way around this error in python?
Dropbox Data File set
*Update. Matlab, when trying to read one of the files using xlsread, says this:
Error using xlsread (line 251)
File C:\Users\zane\Documents\Research Projects\PneuFish Project\Data\Nov 28 2016 ATI
Data\ATI_Data_2016Y_11M_28D_16h_36m_01s.xls not in Microsoft Excel Format.
Thank you!
You can use the module xlrd.
import xlrd
import csv
def csv_from_excel():
wb = xlrd.open_workbook('your_workbook.xls')
sh = wb.sheet_by_name('Sheet1')
your_csv_file = open('your_csv_file.csv', 'wb')
wr = csv.writer(your_csv_file, quoting=csv.QUOTE_ALL)
for rownum in xrange(sh.nrows):
wr.writerow(sh.row_values(rownum))
your_csv_file.close()
Taken from This Post
This will convert from .xls to .csv, which is easily manipulated with Python.
You've said that the file is a text file, so don't tell Python that it's an Excel file. Just use Python's open and read it as text, then do whatever you want with it. open doesn't care what extension a file has.
I'm going to guess that the format is actually tab-delimited. From memory, earlier versions of Excel would read in tab-delimited text files with the .xls extension without complaint, whereas csv files would always bring up the text import wizard, so this was a common dodge if saving data intended for Excel from a program that didn't support writing real Excel files.
If you want the LabVIEW code to write real Excel files in future, the Write to Measurement File express VI has an option to write in xlsx format. I'm not sure which version of LabVIEW first introduced this but it's been there for a few years now.

XLRD vs Win32 COM performance comparison

I have this huge Excel (xls) file that I have to read data from. I tried using the xlrd library, but is pretty slow. I then found out that by converting the Excel file to CSV file manually and reading the CSV file is orders of magnitude faster.
But I cannot ask my client to save the xls as csv manually every time before importing the file. So I thought of converting the file on the fly, before reading it.
Has anyone done any benchmarking as to which procedure is faster:
Open the Excel file with with the xlrd library and save it as CSV file, or
Open the Excel file with win32com library and save it as CSV file?
I am asking because the slowest part is the opening of the file, so if I can get a performance boots from using win32com I would gladly try it.
if you need to read the file frequently, I think it is better to save it as CSV. Otherwise, just read it on the fly.
for performance issue, I think win32com outperforms. however, considering cross-platform compatibility, I think xlrd is better.
win32com is more powerful. With it, one can handle Excel in all ways (e.g. reading/writing cells or ranges).
However, if you are seeking a quick file conversion, I think pandas.read_excel also works.
I am using another package xlwings. so I am also interested with a comparison among these packages.
to my opinion,
I would use pandas.read_excel to for quick file conversion.
If demanding more processing on Excel, I would choose win32com.

Converting HTML to Excel with Django

I have a reporting module in my Django app that gives the user the ability to see their reports on screen or to export them and have the export opened by Excel.
The export is a cheat. I take the exact same output as the screen version and save it to a file with an .xls extension and
response = HttpResponse(body, content_type='application/vnd.ms-excel')
and badda-boom, badda-bing I have an Excel file that is lightly formatted, i.e. it respects the css styling that I've applied.
The nice thing for the user is that the file auto-opens in Excel; there aren't any extra steps for them. (find the download, import a text file, etc.)
Unfortunately it looks like Excel 2016 has decided (I'm guessing) that that's a security issue and no longer opens the file.
I'm aware of various python -> Excel tools. openpyxl looks promising. But that's going to require me to touch each report.
So, what I'm looking for is something that would give me what I have now, take an html file and have Excel open it as a native file and recognize the existing formatting.
The behavior change has been noted by Microsoft and there are work arounds, for the user:
https://support.microsoft.com/en-us/kb/3181507
It sounds like they're working on a fix.

Categories

Resources