How to use delimiter for CSV in Python?

Your code is blanking out your file:

import csv
workingdir = "C:\Mer\Ven\sample"
csvfile = workingdir+"\test3.csv"
f=open(csvfile,'wb') # opens file for writing (erases contents)
csv.writer(f, delimiter=" ",quotechar=",",quoting=csv.QUOTE_MINIMAL)

if you want to read the file in, you will need to use csv.reader and open the file for reading.

import csv
workingdir = "C:\Mer\Ven\sample"
csvfile = workingdir+"\test3.csv"
f=open(csvfile,'rb') # opens file for reading
reader = csv.reader(f)
for line in reader:
    print line

If you want to write that back out to a new file with different delimiters, you can create a new file and specify those delimiters and write out each line (instead of printing the tuple).