Pretty-print PTB trees from a file

pretty-print-ptb.py

#!/usr/bin/env python

import sys
from contextlib import nested
from nltk import tree

def pretty_print(filenames):
    for f in filenames:
        with nested(open(f), open(f + '.pretty', 'w'))  as (inf, outf):
            for line in inf:
                try:
                    t = tree.Tree.parse(line)
                    pretty = t.pprint(margin=50) + '\n'
                except ValueError:
                    pretty = line
                outf.write(pretty)

def main():
    pretty_print(sys.argv)

if __name__ == "__main__":
    main()