filter out unwanted rows

Can you post a fragment of your csv file?  Can you comment on what data must be ignored?

The csv.DictReader() may be overkill for the purpose.  Anyway, the file must be opened for reading in binary mode.  Also the data is not a good identifier for the file object.

What version of Python do you use?  If it is new enough, you should prefer the with construct (the automatic file object close is done).

The following code

    if "{TEST}" == 'TEST':
        break
    else:
        ma.append("{TEST}".format(**a))

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... is equivalent to

    ma.append("{TEST}".format(**a))

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as the "{TEST}" == 'TEST' never holds.

OK
I have attached a csv file - I want to be able to pick any column and return data to an array but with no headers (as in row 1 of csv file) or any cells that are null or blank (no values).
So, if I want to return data into array from column "TEST1" as in the attached my firsdt value world be: -0.011027536
Regards

I can see no attachment.

Sorry
ee.csv

Try the following script:

a.py

import csv

def columnNonEmptyValues(csvFileName, columnName):
    with open(csvFileName, 'rb') as f:
         for d in csv.DictReader(f):
             value = d.get(columnName, '')  # default if not present
             if value:
                 yield value


if __name__ == '__main__':

    # Now you can iterate through the values of the chosen column.
    for value in columnNonEmptyValues('ee.csv', 'TEST1'):
        print value

    # Or you can pass the iterator to the list constructor.
    lst = list(columnNonEmptyValues('ee.csv', 'TEST1'))
    print '-' * 70
    print lst

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It prints on my console:

c:\tmp\_Python\philsivyer\Q_27640149>python a.py
-0.011027536
-0.004086121
-0.012063901
-0.010020955
-0.002050665
-0.004273241
-0.009383166
-0.013938726
...
-0.055930797
-0.066374625
-0.070332921
-0.05798936
----------------------------------------------------------------------
['-0.011027536', '-0.004086121', '-0.012063901', '-0.010020955', '-0.002050665',
 '-0.004273241', '-0.009383166', '-0.013938726', '-0.03455181', '-0.045187455',
'-0.045987727', '-0.043084829', '-0.040607066', '-0.041589412', '-0.031441661',
'-0.032485216', '-0.015742733', '-0.01418973', '-0.012148488', '-0.010371504', '
-0.008392192', '-0.009299116', '-0.009473792', '-0.00851022', '-0.009960434', '-
0.009133718', '-0.005845811', '-0.005267109', '-0.0102875', '-0.014345424', '-0.
010280687', '-0.010643898', '-0.008002167', '-0.007472288', '-0.006297341', '-0.
017303705', '-0.021429973', '-0.013058342', '-0.002337027', '0.002957021', '-0.0
04385036', '-0.010007584', '-0.019457466', '-0.048419451', '-0.073353606', '-0.0
55930797', '-0.066374625', '-0.070332921', '-0.05798936']

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If your Python does not support the with construct, try the older way:

...
def columnNonEmptyValues(csvFileName, columnName):
    f = open(csvFileName, 'rb')
    for d in csv.DictReader(f):
        value = d.get(columnName, '')  # default if not present
        if value:
            yield value
    f.close()

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Thanks - works a treat.
Question - excuse my ignorance but as a newbie to Python ...

can you explain this bit .. if __name__ == '__main__':

and ...
how does it know how to ignore null values or empty strings and not include the JARF header?

Regards

Sorry - one more question
How can I write results to txt file

outfile = open("myresults.txt2,"wb")

etc ??

Regards

If the csv.DictReader(f) does not get the list of columns, it interprets the first line as the record with the column names.

If the d is a dictionary, the d['TEST1'] returns the value for the key 'TEST1'.  But it would fail if the key was not in the dictionary.  The d.get('TEST1', default) is the alternative that returns the same if the key exist or the given default if the item does not exist in the dictionary.

The object behaves as a boolean value in so called boolean context.  In other words, there is a boolean expression expected after the if command.  If it is not a boolean expression, the object interprets itself as a boolean value.  For strings, lists, and other sequence or containers, the empty value is interpreted as False, a non-empty value is interpreted as True.  This way, if the value was or read or set by default as empty string, it is interpreted as False, and it is not yielded by the generator (i.e. ignored).

Thanks
Great response - helps a lot

Many thanks

You are welcome.  Have a good day. ;)