cat <inputFile> | py2mel.py > <outputFile>
py2mel.py -input <inputFile> -output <outputFile>

#!/usr/bin/env python
# Compact Python to Mel converter
#
# Created By Jason Dixon. http://internetimagery.com
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.


# Usage
# cat <inputFile> | py2mel.py > <outputFile>

# OR
# py2mel.py -input <inputFile> -output <outputFile>

import cStringIO
import tokenize
import argparse
import datetime
import sys

parser = argparse.ArgumentParser(
    description="Convert Python file to Melscript (using python interpreter).",
    epilog="Use either standard in and out, the -input -output flags or a combination of both. ie: cat INPUTFILE | py2mel.py > OUTPUTFILE")
parser.add_argument("-i", "--input", help="Input file for processing.", type=argparse.FileType('r'))
parser.add_argument("-o", "--output", help="Output file for processing.", type=argparse.FileType('w'))
parser.add_argument("-s", "--shelf", help="Optional! Name to give to shelf icon if dropping causes shelf icon.", type=str)
args = parser.parse_args()


def remove_comments_and_docstrings(source):
    """
    http://stackoverflow.com/a/2962727
    """
    io_obj = cStringIO.StringIO(source)
    out = ""
    prev_toktype = tokenize.INDENT
    last_lineno = -1
    last_col = 0
    for tok in tokenize.generate_tokens(io_obj.readline):
        token_type = tok[0]
        token_string = tok[1]
        start_line, start_col = tok[2]
        end_line, end_col = tok[3]
        ltext = tok[4]
        if start_line > last_lineno:
            last_col = 0
        if start_col > last_col:
            out += (" " * (start_col - last_col))
        if token_type == tokenize.COMMENT:
            pass
        elif token_type == tokenize.STRING:
            if prev_toktype != tokenize.INDENT:
                if prev_toktype != tokenize.NEWLINE:
                    if start_col > 0:
                        out += token_string
        else:
            out += token_string
        prev_toktype = token_type
        last_col = end_col
        last_lineno = end_line
    return out


def stringify(data):
    return remove_comments_and_docstrings(data).replace("\\", "\\\\").replace("\"", "\\\"").replace("\n", r"\n")


def version():
    version = "v1.0.2"
    return "py2mel.py %s, compiled %s\n\n" % (version, datetime.datetime.today())


def python_interpret(data):
    output = "// %s" % version()
    output += "python(\"%s\");" % stringify(data)
    return output


def python_shelf(data, name):
    code = "# %s" % version()
    code += data
    return "shelfButton -l \"%s\" -c \"%s\" -stp \"python\" -i \"daisyLarge.png\" -p `tabLayout -query -selectTab $gShelfTopLevel`;" % (name, stringify(code))

inp = args.input if args.input else sys.stdin
out = args.output if args.output else sys.stdout
data = python_shelf(inp.read(), args.shelf) if args.shelf else python_interpret(inp.read())
out.write(data)