Writing a CSV from Flask framework [duplicate]

Question

I have no problems writing a CSV outside of the Flask framework. But when I try to write it from Flask, it writes to the CSV, but only on one line.

Here is the template I'm following

@app.route('/download') def download():     csv = """"REVIEW_DATE","AUTHOR","ISBN","DISCOUNTED_PRICE" "1985/01/21","Douglas Adams",0345391802,5.95 "1990/01/12","Douglas Hofstadter",0465026567,9.95 "1998/07/15","Timothy ""The Parser"" Campbell",0968411304,18.99 "1999/12/03","Richard Friedman",0060630353,5.95 "2004/10/04","Randel Helms",0879755725,4.50"""     response = make_response(csv)     response.headers["Content-Disposition"] = "attachment; filename=books.csv"     return response 

This writes the CSV perfectly, but when I try with my code, I get one long row.

My code:

@app.route('/download') def post(self):      # lots of code      csvList.append([all,my,data,goes,here])      csvList = str(re.sub('\[|\]','',str(csvList)))  # convert to a string; remove brackets      response = make_response(csvList)     response.headers['Content-Disposition'] = "attachment; filename=myCSV.csv"     return response 

My output:

Nashville Physician Service Ce,Treasury Specialist,Brentwood,TN,(615) 507-1646,La Petite Academy,Afternoon Teacher Aide,Goodlettsville,TN,(615) 859-2034,Nashville Physician Service Ce,Denial Resolution Specialist,Brentwood,TN,(615) 507-1646 

Thanks.

EDIT: I tried just about all the answers and they worked for the most part, but I chose vectorfrog's because it fit with what I was trying to accomplish.

Answer 1

I did something like this recently, I found that I needed to first place the csv into a StringIO and then return the StringIO. If you want the csv to be a download, here's what I did:

import StringIO import csv from flask import make_response  @app.route('/download') def post(self):     si = StringIO.StringIO()     cw = csv.writer(si)     cw.writerows(csvList)     output = make_response(si.getvalue())     output.headers["Content-Disposition"] = "attachment; filename=export.csv"     output.headers["Content-type"] = "text/csv"     return output 

Answer 2

You need to add newlines. Anyway, your method of making csvs (printing the list and removing brackets from it) is not the best way to do it. Try this instead:

csvList = '\n'.join(','.join(row) for row in csvList) 

Or use the csv module:

import io, csv  dest = io.StringIO() writer = csv.writer(dest)  for row in csvList:     writer.writerow(row)  # Now dest is a file-like object containing your csv