Example for https://www.biostars.org/p/138849/

gffparse_example.py

from gffutils.iterators import DataIterator

input_filename = 'example.gff'
output_filename = 'output.gff'

with open(output_filename, 'w') as fout:
    for feature in DataIterator(input_filename):
        # len() works to get the length of a feature in bp
        if len(feature) < 1000:
            continue
        
        # Attribute access with dictionary-like syntax
        if 'LINE' not in feature['Superfamily']:
            continue

        fout.write(str(line) + '\n')