Python save XLSX to CSV - python

I am not a python user. However, I am sick of saving Excel files to CSV manually, and everybody hates Perl at this shop. I can't get Spreadsheet::XLSX to work in this work environment. They only use Python.
The python version is 2.4.
#!/usr/bin/python
import openpyxl
import csv
wb = openpyxl.load_workbook('DailySnapshot.xlsx')
sh = wb.get_active_sheet()
with open('test.csv', 'wb') as f:
c = csv.writer(f)
for r in sh.rows:
c.writerow([cell.value for cell in r])
The DailySnapshot.xlxs is saved in the same directory a the script. It is a one page excel spreadsheet, and the sheet is called 'Table1'. I figured I would name the CSV file test.csv. This is the error it throws.
File "./secondPyTry.py", line 8
with open('test.csv', 'wb') as f:
^ SyntaxError: invalid syntax

As it was said in the comments, Python 2.4 does not wupport with. You should open the file like this instead:
f = open('test.csv', 'wb')
c = csv.writer(f)
for r in sh.rows:
c.writerow([cell.value for cell in r])
f.close()

Related

Adding csv filename to a column in python (200 files)

I have 200 files with dates in the file name. I would like to add date from this file name into new column in each file.
I created macro in Python:
import pandas as pd
import os
import openpyxl
import csv
os.chdir(r'\\\\\\\')
for file_name in os.listdir(r'\\\\\\'):
with open(file_name,'r') as csvinput:
reader = csv.reader(csvinput)
all = []
row = next(reader)
row.append('FileName')
all.append(row)
for row in reader:
row.append(file_name)
all.append(row)
with open(file_name, 'w') as csvoutput:
writer = csv.writer(csvoutput, lineterminator='\n')
writer.writerows(all)
if file_name.endswith('.csv'):
workbook = openpyxl.load_workbook(file_name)
workbook.save(file_name)
csv_filename = pd.read_csv(r'\\\\\\')
csv_data= pd.read_csv(csv_filename, header = 0)
csv_data['filename'] = csv_filename`
Right now I see "InvalidFileException: File is not a zip file" and only first file has added column with the file name.
Can you please advise what am I doing wrong? BTW I,m using Python 3.4.
Many thanks,
Lukasz
First problem, this section:
with open(file_name, 'w') as csvoutput:
writer = csv.writer(csvoutput, lineterminator='\n')
writer.writerows(all)
should be indented, to be included in the for loop. Now it is only executed once after the loop. This is why you only get one output file.
Second problem, the exception is probably caused by openpyxl.load_workbook(file_name). Presumably openpyxl can only open actual Excel files (which are .zip files with other extension), no CSV files. Why do you want to open and save it after all? I think you can just remove those three lines.

What's the equivalent of reader = csv.reader(...) for xlsx sheets?

I have a script with
path=r"mypath\myfile.xlsx"
with open(path) as f:
reader = csv.reader(f)
but it won't work because the code is trying to open an xlsx file with a module made for csv files.
So, does an expression equivalent for xlsx files exist?
The equivalent of the highlighted code for xlsx sheets is:
path=r"mypath\myfile.xlsx"
import pandas as pd
with open(path) as f:
reader = pd.read_excel(f)

Converting a .csv.gz to .csv in Python 2.7

I have read the documentation and a few additional posts on SO and other various places, but I can't quite figure out this concept:
When you call csvFilename = gzip.open(filename, 'rb') then reader = csv.reader(open(csvFilename)), is that reader not a valid csv file?
I am trying to solve the problem outlined below, and am getting a coercing to Unicode: need string or buffer, GzipFile found error on line 41 and 7 (highlighted below), leading me to believe that the gzip.open and csv.reader do not work as I had previously thought.
Problem I am trying to solve
I am trying to take a results.csv.gz and convert it to a results.csv so that I can turn the results.csv into a python dictionary and then combine it with another python dictionary.
File 1:
alertFile = payload.get('results_file')
alertDataCSV = rh.dataToDict(alertFile) # LINE 41
alertDataTotal = rh.mergeTwoDicts(splunkParams, alertDataCSV)
Calls File 2:
import gzip
import csv
def dataToDict(filename):
csvFilename = gzip.open(filename, 'rb')
reader = csv.reader(open(csvFilename)) # LINE 7
alertData={}
for row in reader:
alertData[row[0]]=row[1:]
return alertData
def mergeTwoDicts(dictA, dictB):
dictC = dictA.copy()
dictC.update(dictB)
return dictC
*edit: also forgive my non-PEP style of naming in Python
gzip.open returns a file-like object (same as what plain open returns), not the name of the decompressed file. Simply pass the result directly to csv.reader and it will work (the csv.reader will receive the decompressed lines). csv does expect text though, so on Python 3 you need to open it to read as text (on Python 2 'rb' is fine, the module doesn't deal with encodings, but then, neither does the csv module). Simply change:
csvFilename = gzip.open(filename, 'rb')
reader = csv.reader(open(csvFilename))
to:
# Python 2
csvFile = gzip.open(filename, 'rb')
reader = csv.reader(csvFile) # No reopening involved
# Python 3
csvFile = gzip.open(filename, 'rt', newline='') # Open in text mode, not binary, no line ending translation
reader = csv.reader(csvFile) # No reopening involved
The following worked for me for python==3.7.9:
import gzip
my_filename = my_compressed_file.csv.gz
with gzip.open(my_filename, 'rt') as gz_file:
data = gz_file.read() # read decompressed data
with open(my_filename[:-3], 'wt') as out_file:
out_file.write(data) # write decompressed data
my_filename[:-3] is to get the actual filename so that it does get a random filename.

how to convert xlsx to tab delimited files

I have quite a lot of xlsx files which is a pain to convert them one by one to tab delimited files
I would like to know if there is any solution to do this by python. Here what I found and what tried to do with failure
This I found and I tried the solution but did not work Mass Convert .xls and .xlsx to .txt (Tab Delimited) on a Mac
I also tried to do it for one file to see how it works but with no success
#!/usr/bin/python
import xlrd
import csv
def main():
# I open the xlsx file
myfile = xlrd.open_workbook('myfile.xlsx')
# I don't know the name of sheet
mysheet = myfile.sheet_by_index(0)
# I open the output csv
myCsvfile = open('my.csv', 'wb')
# I write the file into it
wr = csv.writer(myCsvfile, delimiter="\t")
for rownum in xrange(mysheet.nrows):
wr.writerow(mysheet.row_values(rownum))
myCsvfile.close()
if __name__ == '__main__':
main()
No real need for the main function.
And not sure about your indentation problems, but this is how I would write what you have. (And should work, according to first comment above)
#!/usr/bin/python
import xlrd
import csv
# open the output csv
with open('my.csv', 'wb') as myCsvfile:
# define a writer
wr = csv.writer(myCsvfile, delimiter="\t")
# open the xlsx file
myfile = xlrd.open_workbook('myfile.xlsx')
# get a sheet
mysheet = myfile.sheet_by_index(0)
# write the rows
for rownum in xrange(mysheet.nrows):
wr.writerow(mysheet.row_values(rownum))
Why go with so much pain when you can do it in 3 lines:
import pandas as pd
file = pd.read_excel('myfile.xlsx')
file.to_csv('myfile.xlsx',
sep="\t",
index=False)

How to create a csv file in Python, and export (put) it to some local directory

This problem may be tricky.
I want to create a csv file from a list in Python. This csv file does not exist before. And then export it to some local directory. There is no such file in the local directory either. We just create a new csv file, and export (put) the csv file in some local directory.
I found that StringIO.StringIO can generate the csv file from a list in Python, then what are the next steps.
Thank you.
And I found the following code can do it:
import os
import os.path
import StringIO
import csv
dir = r"C:\Python27"
if not os.path.exists(dir):
os.mkdir(dir)
my_list=[[1,2,3],[4,5,6]]
with open(os.path.join(dir, "filename"+'.csv'), "w") as f:
csvfile=StringIO.StringIO()
csvwriter=csv.writer(csvfile)
for l in my_list:
csvwriter.writerow(l)
for a in csvfile.getvalue():
f.writelines(a)
Did you read the docs?
https://docs.python.org/2/library/csv.html
Lots of examples on that page of how to read / write CSV files.
One of them:
import csv
with open('some.csv', 'wb') as f:
writer = csv.writer(f)
writer.writerows(someiterable)
import csv
with open('/path/to/location', 'wb') as f:
writer = csv.writer(f)
writer.writerows(youriterable)
https://docs.python.org/2/library/csv.html#examples

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