Write out clip file for Houdini from Maya

houdini_clip_creator.py

"""
@author: 
    John P. Neumann (aka ArrantSquid)

@description:
    Writes out a clip file (for use in Houdini) based on maya attributes
    passed in. 
  
@usage:
    main('some_object', ['scaleX','visibility'], 'some_dir')
    main('some_object', ['translate'], 'some_dir')
 
"""
import os
import sys

from maya import cmds
def main(obj, channel, frame_rate, output_dir):
    """
    gets an objects channel data and outputs it to a clip file.

    @type obj: str
    @param obj: The object we want the data for
                (eg. someCharacter:MoveScaleRotate")
    @type channel: list
    @param channel: List of attributes we want the data for.
    @type frame_rate: float
    @param frame_rate: The frame rate you wish to export at.
                       (eg. 24.0 - film, 29.97 - ntsc)
    @type output_dir: str
    @param output_dir: The directory we want to output the data to.

    @rtype: bool
    @returns: True or False.

    """
    start_frame = cmds.playbackOptions(q=True, ast=True)
    end_frame = cmds.playbackOptions(q=True, aet=True)
    if isinstance(channel, str):
        tmp_chan = channel
        channel = []
        channel.append(tmp_chan)

    if ':' in obj:
        obj_name= obj.split(':')[0]
    else:
        obj_name= obj

    out_file = os.path.join(output_dir, '%s.clip' % (obj_name))
    try:
        fopen = open(out_file, 'w')
    except IOError, err:
        msg = ('Error opening file %s\nError: %s\n' % (out_file, err))
        sys.stderr.write(msg)
        return False

    tracks = len(channel)
    fopen.write('{\n')
    fopen.write('\trate = %.02f\n' % (frame_rate))
    fopen.write('\tstart = %d\n' % (start_frame))
    fopen.write('\ttracklength = %d\n' % (end_frame))
    fopen.write('\ttracks = %d\n' % (tracks))

    for chan in channel:
        key_data = cmds.keyframe('%s.%s' % (obj, chan),
                                 t=(start_frame, end_frame),
                                 vc=True, q=True)
        fopen.write('\t{\n')
        fopen.write('\t\tname = %s\n' % (chan))
        fopen.write('\t\tdata = %s\n' % (' '.join(map(str, key_data))))
        fopen.write('\t}\n')
    fopen.write('}\n')
    fopen.close()

    return True