Though you already have an accepted answer, I figured I'd add this for anyone else interested in a different solution-

• The csv module's DictReader object has a public attribute called fieldnames (as of Python 2.6 and above). https://docs.python.org/3.4/library/csv.html#csv.csvreader.fieldnames

An implementation could be as follows:

import csv

with open('C:/mypath/to/csvfile.csv', 'r') as f:
    dict_reader = csv.DictReader(f)

    #get header fieldnames from DictReader and store in list
    headers = dict_reader.fieldnames

    #sample file reading logic
    for line in dict_reader:
        print(line[headers[0]])
        

In the above, dict_reader.fieldnames returns a list of your headers (assuming the headers are in the top row). Which allows...

>>> print(headers)
['MyColumn1', 'MyColumn2', 'MyColumn3']

If your headers are in, say the 2nd row (with the very top row being row 1), you could do as follows:

import csv

with open('C:/mypath/to/csvfile.csv', 'r') as f:
    #you can eat the first line before creating DictReader.
    #if no "fieldnames" param is passed into
    #DictReader object upon creation, DictReader
    #will read the upper-most line as the headers
    f.readline()
    
    dict_reader = csv.DictReader(f)
    headers = dict_reader.fieldnames

    #sample file reading logic
    for line in dict_reader:
        print(line[headers[0]])

Edit:
In 2.7 / 3.2 there is a new writeheader() method. Also, John Machin's answer provides a simpler method of writing the header row.
Simple example of using the writeheader() method now available in 2.7 / 3.2:

from collections import OrderedDict
ordered_fieldnames = OrderedDict([('field1',None),('field2',None)])
with open(outfile,'wb') as fou:
    dw = csv.DictWriter(fou, delimiter='\t', fieldnames=ordered_fieldnames)
    dw.writeheader()
    # continue on to write data

Instantiating DictWriter requires a fieldnames argument.
From the documentation:

The fieldnames parameter identifies the order in which values in the dictionary passed to the writerow() method are written to the csvfile.

Put another way: The Fieldnames argument is required because Python dicts are inherently unordered.
Below is an example of how you'd write the header and data to a file.
Note: with statement was added in 2.6. If using 2.5: from __future__ import with_statement

with open(infile,'rb') as fin:
    dr = csv.DictReader(fin, delimiter='\t')

# dr.fieldnames contains values from first row of `f`.
with open(outfile,'wb') as fou:
    dw = csv.DictWriter(fou, delimiter='\t', fieldnames=dr.fieldnames)
    headers = {} 
    for n in dw.fieldnames:
        headers[n] = n
    dw.writerow(headers)
    for row in dr:
        dw.writerow(row)

As @FM mentions in a comment, you can condense header-writing to a one-liner, e.g.:

with open(outfile,'wb') as fou:
    dw = csv.DictWriter(fou, delimiter='\t', fieldnames=dr.fieldnames)
    dw.writerow(dict((fn,fn) for fn in dr.fieldnames))
    for row in dr:
        dw.writerow(row)

You may be able to use a csv.Sniffer here.

The has_header method peeks at the data and uses heuristics to determine whether a header is present (refer to the doc for the exact logic).

Note that in the example data shown in the question, the sniffer heuristic would incorrectly consider both headerless and headerful to have a header. That's probably a consequence of your sample data having only a single row, if I add a second numeric row 4,5,6 in the input data then the Sniffer.has_header method works as expected.

A basic implementation which assumes csvfile is seekable could look like this:

def print_data_rows(csvfile):
    reader = csv.DictReader(csvfile, fieldnames=FIELDNAMES)
    sniffer = csv.Sniffer()
    sample = csvfile.read(1024)
    csvfile.seek(0)
    if sniffer.has_header(sample):
        next(reader)
    for row in reader:
        print(row)

It's easy to adapt if your stream isn't seekable, just buffer the first line.

Based on your edit, you need to skip the initial space after the comma.

This should do it:

>>> reader = csv.DictReader(open(PathFile),skipinitialspace=True)