Trying to copy column1 from a csv file to another empty file using python

First, you want to open your files. A good practice is to use the with statement (that, technically speaking, introduces a context manager) so that when your code exits from the with block all the files are automatically closed

with open('test.csv') as inpfile, open('out.csv', 'w') as outfile:

next you want a loop on the lines of the input file (note the indentation, we are inside the with block), line splitting is automatic when you read a text file with lines separated by newlines…

    for line in inpfile:

each line is a string, but you think of it as two fields separated by white space — this situation is so common that strings have a method to deal with this situation (note again the increasing indent, we are in the for loop block)

        fields = line.split()

by default .split() splits on white space, but you can use, e.g., split(',') to split on commas, etc — that said, fields is a list of strings, for your first record it is equal to ['A', '32'] and you want to output just the first field in this list… for this purpose a file object has the .write() method, that writes a string, just a string, to the file, and fields[0] IS a string, but we have to add a newline character to it because, in this respect, .write() is different from print().

        outfile.write(fields[0]+'\n')

That's all, but if you omit my comments it's 4 lines of code

with open('test.csv') as inpfile, open('out.csv', 'w') as outfile:
    for line in inpfile:
        fields = line.split()
        outfile.write(fields[0]+'\n')

When you are done with learning (some) Python, ask for an explanation of this...

with open('test.csv') as ifl, open('out.csv', 'w') as ofl:
    ofl.write('\n'.join(line.split()[0] for line in ifl))

Addendum

The csv module in such a simple case adds the additional conveniences of

1. auto-splitting each line into a list of strings
2. taking care of the details of output (newlines, etc)

and when learning Python it's more fruitful to see how these steps can be done using the bare language, or at least that it is my opinion…

The situation is different when your data file is complex, has headers, has quoted strings possibly containing quoted delimiters etc etc, in those cases the use of csv is recommended, as it takes into account all the gory details. For complex data analisys requirements you will need other packages, not included in the standard library, e.g., numpy and pandas, but that is another story.

This answer reads the CSV file, understanding a column to be demarked by a space character. You have to add the header=None otherwise the first row will be taken to be the header / names of columns.

ss is a slice - the 0th column, taking all rows as denoted by :

The last line writes the slice to a new filename.

import pandas as pd

df = pd.read_csv('test.csv', sep=' ', header=None)
ss = df.ix[:, 0]
ss.to_csv('new_path.csv', sep=' ', index=False)

import csv

reader = csv.reader(open("test.csv","rb"), delimiter='\t')
writer = csv.writer(open("output.csv","wb"))

for e in reader:
    writer.writerow(e[0])

The best you can do is create a empty list and append the column and then write that new list into another csv for example:

import csv

def writetocsv(l):
#convert the set to the list
b = list(l)
print (b)
with open("newfile.csv",'w',newline='',) as f:
        w = csv.writer(f, delimiter=',')
        for value in b:
             w.writerow([value])

adcb_list = []

f= open("test.csv",'r')
reader = csv.reader(f,delimiter="\t")
for each_line in reader:
              adcb_list.append(each_line)
writetocsv(adcb_list)

hope this works for you :-)