Run Python script from cmd in windows

Question

I need to generate features from text. The script I am using below is available online but actually I do not know how to run it because I do not know python at all. I have a text file called (train.txt) contains the following

He PRP B-NP
reckons VBZ B-VP
the DT B-NP
current JJ I-NP
account NN I-NP
deficit NN I-NP
will MD B-VP
narrow VB I-VP
to TO B-PP
only RB B-NP
# # I-NP
1.8 CD I-NP
billion CD I-NP
in IN B-PP
September NNP B-NP
. . O

and I have a python script that convert the above text to features like the following features:

B-NP    w[0]=He w[1]=reckons    w[2]=the        w[0]|w[1]=He|reckons    pos[0]=P
RP      pos[1]=VBZ      pos[2]=DT       pos[0]|pos[1]=PRP|VBZ   pos[1]|pos[2]=VB
Z|DT    pos[0]|pos[1]|pos[2]=PRP|VBZ|DT __BOS__
...

The python script is

# Separator of field values.
separator = ' '

# Field names of the input data.
fields = 'w pos y'

# Attribute templates.
templates = (
    (('w', -2), ),
    (('w', -1), ),
    (('w',  0), ),
    (('w',  1), ),
    (('w',  2), ),
    (('w', -1), ('w',  0)),
    (('w',  0), ('w',  1)),
    (('pos', -2), ),
    (('pos', -1), ),
    (('pos',  0), ),
    (('pos',  1), ),
    (('pos',  2), ),
    (('pos', -2), ('pos', -1)),
    (('pos', -1), ('pos',  0)),
    (('pos',  0), ('pos',  1)),
    (('pos',  1), ('pos',  2)),
    (('pos', -2), ('pos', -1), ('pos',  0)),
    (('pos', -1), ('pos',  0), ('pos',  1)),
    (('pos',  0), ('pos',  1), ('pos',  2)),
    )


import crfutils

def feature_extractor(X):
    # Apply attribute templates to obtain features (in fact, attributes)
    crfutils.apply_templates(X, templates)
    if X:
    # Append BOS and EOS features manually
        X[0]['F'].append('__BOS__')     # BOS feature
        X[-1]['F'].append('__EOS__')    # EOS feature

if __name__ == '__main__':
    crfutils.main(feature_extractor, fields=fields, sep=separator)

Both script.py and crfutils.py exist in the same folder I run the above script from cmd on Windows 7 as follow:

C:\>Python script.py train.txt > train.result.txt

I've got an empty file titled train.result.txt and because I am new to python (actually just start learning it). I do not know what is the problem? am I providing the arguments in a wrong order? Is the format of the train.txt file wrong?

Answer 1

You need to pass in train.txt on stdin, not as a command line argument:

C:\>Python script.py < train.txt > train.result.txt