"Judith Flores" <jur...@yahoo.com> wrote
I have been struggling a while trying to figure out how to modify
a csv
file using the csv.DictWriter class. Let's suppose I have the
following code:
I have never used DictWriter but...
outfile=open('template.csv','w') # This is a pre-existing file
Opening a file to write will create a new empty file. It will
effectively delete
the pre existing file!
1. When I run the code above for the first time, the contents of the
pre-existing
file disappear, if I run the script a second time, now I can see the
value of x.
Not sure why you see it on the second run but you are deleting the
file
with the open call. You probably need to open one file for reading and
another for writing thenm at the end delete the first file (or rename
it to .bak)
and overwrite with the written (modified) file.
2. The fieldnames don't appear in the csv file, only the values.
3. Is there a way to let the DictWriter know that the header of the
csv
file corresponds to all the fieldnames? To avoid typing all the
names.
I can't help with that bit, sorry.
--
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
