How to write in ARFF file using LIAC-ARFF package in Python?

Question

I want to load an ARFF file in python, then change some values of it and then save changes to file. I'm using LIAC-ARFF package ( https://pypi.python.org/pypi/liac-arff ). I loaded ARFF file with following lines of code:

import arff
data = arff.load(open(FILE_NAME, 'rb'))

After manipulating some values inside data , i want to write data to another ARFF file. Any solution?

Answer 1

Use the following code:

import arff
data = arff.load(open(FILE_NAME, 'rb'))
f = open(outputfilename, 'wb')
arff.dump(data, f)
f.close()

In the LICA-ARFF description you see dump method which serializes to a the file, but it's wrong. It just write object as text file. Serialize means save whole the object, so the output file is binary not a text file.

Answer 2

We can load arff data into python using scipy.

from scipy.io import arff

import pandas as pd

data = arff.loadarff('dataset.arff')

df = pd.DataFrame(data[0])

df.head()