[FIXED] Extract one column of csv into a comma separated list python

Issue

I have a CSV file that I read like below:

with open ("ann.csv", "rb") as annotate:
    for col in annotate:
        ann = col.lower().split(",")
        print ann[0]

My CSV file looks like below:

H1,H2,H3
da,ta,one
dat,a,two

My output looks like this:

da
dat

but I want a comma separated output like (da,dat). How can I do that?

Solution

First, in Python you have the csv module - use that.

Second, you're iterating through rows, so using col as a variable name is a bit confusing.

Third, just collect the items in a list and print that using .join():

import csv
with open ("ann.csv", "rb") as csvfile:
    reader = csv.reader(csvfile)
    reader.next() # Skip the header row
    collected = []
    for row in reader:
        collected.append(row[0])
    print ",".join(collected)

Answered By - Tim Pietzcker