Convert Excel zip file content to actual Excel file? - python

I am using cmis package available in python to download the document from FileNet repository. I am using getcontentstream method available in the package. However it returns content file that beings with 'Pk' and ends in 'PK'. when I googled I came to know it is excel zip package content. is there a way to save the content into an excel file. I should be able to open the downloaded excel. I am using below code. but getting byte-liked object is required not str. I noticed type of result is string.io.
# expport the result
result = testDoc.getContentStream()
outfile = open(sample.xlsx, 'wb')
outfile.write(result.read())
result.close()
outfile.close()

Hi there and welcome to stackoverflow. There are a few bits I noticed about your post.
To answer the error code you are getting directly. You called the outfile FileStream to be in terms of binary, however the result.read() must be in Unicode string format which is why you are getting this error. You can try to encode it before passing it to the outfile.write() function (ex: outfile.write(result.read().encode())).
You can also simply just write Unicode directly by:
result = testDoc.getContentStream()
result_text = result.read()
from zipfile import ZipFile
with ZipFile(filepath, 'w') as zf:
zf.writestr('filename_that_is_zipped', result_text)
Not I am not sure what you have in your ContentStream but note that a excel file is made up of xml files zipped up. The minimum file structure you need for an excel file is as follows:
_rels/.rels contains excel schemas
docProps/app.xml contains number of sheets and sheet names
docProps/core.xml boiler plate user info and date created
xl/workbook.xml contains sheet names rdId to workbook link
xl/worksheets/sheet1.xml (and more sheets in this folder) contains cell data for each sheet
xl/_rels/workbook.xml.rels contains sheet file locations within zipfile
xl/sharedStrings.xml if you have string only cell values
[Content_Types].xmlapplies schemas to file types
I recently went through piecing together an excel file from scratch, if you want to see the code check out https://github.com/PydPiper/pylightxl

Related

exporting to csv converts text to date

From Python i want to export to csv format a dataframe
The dataframe contains two columns like this
So when i write this :
df['NAME'] = df['NAME'].astype(str) # or .astype('string')
df.to_csv('output.csv',index=False,sep=';')
The excel output in csv format returns this :
and reads the value "MAY8218" as a date format "may-18" while i want it to be read as "MAY8218".
I've tried many ways but none of them is working. I don't want an alternative like putting quotation marks to the left and the right of the value.
Thanks.
If you want to export the dataframe to use it in excel just export it as xlsx. It works for me and maintains the value as string in the original format.
df.to_excel('output.xlsx',index=False)
The CSV format is a text format. The file contains no hint for the type of the field. The problem is that Excel has the worst possible support for CSV files: it assumes that CSV files always use its own conventions when you try to read one. In short, one Excel implementation can only read correctly what it has written...
That means that you cannot prevent Excel to interpret the csv data the way it wants, at least when you open a csv file. Fortunately you have other options:
import the csv file instead of opening it. This time you have options to configure the way the file should be processed.
use LibreOffice calc for processing CSV files. LibreOffice is a little behind Microsoft Office on most points except for csv file handling where it has an excellent support.

Python - trying to import/open incorrectly formatted .xls file

I'm trying to write some Python code which needs to take data from an .xls file created by another application (outside of my control). I've tried using pandas and xlrd and neither are able to open the file, I get the error messages:
"Excel file format cannot be determined, you must specify an engine manually." using Pandas.
"Unsupported format, or corrupt file: Expected BOF record; found b'\r\n\t'" using xlrd
I think it has to do with the way the file is exported from the program that creates it. When opened directly through Excel, I get the error message "The file format and extension don't match". However, you can ignore this message and the file opens in a usable format and can be edited and all of the expected values are in the right cells etc. Interestingly, when I go to save the file in Excel, the default option that comes up is a webpage.
Currently I have a workaround in that I can just open the file in Excel, save it as a .csv then read it into Python as a csv. This does have to be done through Excel through, if I just change the file extension to .csv, the resulting file is garbage.
However, ideally I would like to avoid the user having to do anything manaully. Would be greatly appreciated if anyone has any suggestions of ways that this might be possible (i.e. can I 'open' the file in Excel and save it through Excel using Python commands?) or if there are any packages or comands I can use to open/fix badly formatted .xls files.
Cheers!
P.S. I'm pretty new to Python and only have experience in R otherwise so my current knowledge is quite limited, apologies in advance!
try this :
from pathlib import Path
import pandas as pd
file_path = Path(filename)
df = pd.read_excel(file.read(), engine='openpyxl')

How to filter out useable data from csv files using python?

Please help me in extracting important data from a .csv file using python. I got .csv file from 'citrine'.
I want to extract the element name and atomic percentage in the form of "Al2.5B0.02C0.025Co14.7Cr16.0Mo3.0Ni57.48Ti5.0W1.25Zr0.03"
ORIGINAL
[{""element"":""Al"",""idealAtomicPercent"":{""value"":""5.4""}},{""element"":""B"",""idealAtomicPercent"":{""value"":""0.02""}},{""element"":""C"",""idealAtomicPercent"":{""value"":""0.13""}},{""element"":""Co"",""idealAtomicPercent"":{""value"":""7.5""}},{""element"":""Cr"",""idealAtomicPercent"":{""value"":""6.1""}},{""element"":""Mo"",""idealAtomicPercent"":{""value"":""2.0""}},{""element"":""Nb"",""idealAtomicPercent"":{""value"":""0.5""}},{""element"":""Ni"",""idealAtomicPercent"":{""value"":""61.0""}},{""element"":""Re"",""idealAtomicPercent"":{""value"":""0.5""}},{""element"":""Ta"",""idealAtomicPercent"":{""value"":""9.0""}},{""element"":""Ti"",""idealAtomicPercent"":{""value"":""1.0""}},{""element"":""W"",""idealAtomicPercent"":{""value"":""5.8""}},{""element"":""Zr"",""idealAtomicPercent"":{""value"":""0.13""}}]
Original CSV
Expected output
Without having the file structure it is hard to tell.
Try to load the file using:
import csv
with open(file_path) as file:
reader = csv.DictReader(...)
You will have to figure out the arguments for the function which depend on the file.

openpyxl cannot read Strict Open XML Spreadsheet format: UserWarning: File contains an invalid specification for Sheet1. This will be removed

A few of my users (all of whom use Mac) have uploaded an Excel into my application, which then rejected it because the file appeared to be empty. After some debugging, I've determined that the file was saved in Strict Open XML Spreedsheet format, and that openpyxl (2.6.0) doesn't issue an error, but rather prints a warning to stderr.
To reproduce, open a file, add a few rows and save as Strict Open XML Spreedsheet (*.xlsx) format.
import openpyxl
with open('excel_open_strict.xlsx', 'rb') as f:
workbook = openpyxl.load_workbook(filename=f)
This will print the following warning, but will not throw any exception:
UserWarning: File contains an invalid specification for Sheet1. This will be removed
Furthermore, the workbook appears to have no sheets:
assert workbook.get_sheet_names() == []
I've now had three Mac users experience this issue. It seems like Mac will sometimes default to using this Strict Open XML Spreedsheet format. If this is a normal case, then openpyxl should be able to handle it. Otherwise, it would be great if openpyxl would just throw an exception. As a workaround, it seems I can do the following:
import openpyxl
with open('excel_open_strict.xlsx', 'rb') as f:
workbook = openpyxl.load_workbook(filename=f)
if not workbook.get_sheet_names():
raise Exception("The Excel was saved in an incorrect format")
I had similar problems with XLSX files created using the R library openxlsx. A sample error message from a simple python program to open the file and retrieve a single value from sheet Crops:
Warning (from warnings module):
File "C:\Python38\lib\site-packages\openpyxl\reader\workbook.py", line 88
warn(msg)
UserWarning: File contains an invalid specification for Crops. This will be removed
My first, very clumsy solution:
Open with Excel
Save the file as *.xls, which triggered a warning about compatibility.
Re-save as *.xlsx
My second solution works if you only need to read the file:
Impose a read-only restriction:
wb = load_workbook(filename = 'CAF_LTAR_crops_out_0.3.xlsx', read_only=True)
The broad lesson seems to be that the XLSX file specification is not uniformly (correctly?) implemented across programming languages.
I am working with a Windows PC and I had the same Problem with openpyxl. I got an excel template that was saved as Strict Open XML Spreadsheet (*.xlsx). I tried to fill out the template but I got always a fault message for each work sheet as below and when I tried to print the array with all worksheet names was empty [].
UserWarning: File contains an invalid specification for Sheetname. This will be removed
Solution
I saved the file as Excel Workbook (*.xlsx) and not as Strict Open XML Spreadsheet (*.xlsx). After that I had no fault message, the array included all Worksheets and I could fill out the template with openpyxl.

Python: How to handle excel data from web without saving file

I'm new to python and having trouble dealing with excel manpulation in python.
So here's my situation: I'm using requests to get a .xls file from a web server. After that I'm using xlrd to save the content in excel file. I'm only interested in one value of that file, and there are thousands of files im retrieving from different url addresses.
I want to know how could i handle the contents i get from request in some other way rather than creating a new file.
Besides, i've included my code my comments on how could I improve it. Besides, it doesn't work, since i'm trying to save new content in an already created excel file (but i couldnt figure out how to delete the contents of that file for my code to work (even if its not efficient)).
import requests
import xlrd
d={}
for year in string_of_years:
for month in string_of_months:
dls=" http://.../name_year_month.xls"
resp = requests.get(dls)
output = open('temp.xls', 'wb')
output.write(resp.content)
output.close()
workbook = xlrd.open_workbook('temp.xls')
worksheet = workbook.sheet_by_name(mysheet_name)
num_rows = worksheet.nrows
for k in range(num_rows):
if condition I'm looking for:
w={key_year_month:worksheet.cell_value(k,0)}
dic.update(w)
break
xlrd.open_workbook can accept a string for the file data instead of the file name. Your code could pass the contents of the XLS, rather than creating a file and passing its name.
Try this:
# UNTESTED
resp = requests.get(dls)
workbook = xlrd.open_workbook(file_contents=resp.content)
Reference: xlrd.open_workbook documentation
Save it and then delete the file readily on each loop after the work with os.
import os
#Your Stuff here
os.remove(#path to temp_file)

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