Doing something with Gantt, not sure what yet

gistfile1.py

import datetime


class Gantt(object):
    """ Generate and manipulate Gantt charts """
    def __init__(self, *args, **kwargs):
        self.start = kwargs.pop(
                'start',
                datetime.datetime.now() - datetime.timedelta(7)
            )
        self.end = kwargs.pop(
                'end',
                datetime.datetime.now() + datetime.timedelta(7)
            )
        self.duration = self.end - self.start

    def _get_offset(self, start, end):
        duration = start - self.start
        per = (duration.total_seconds() / self.duration.total_seconds()) * 100
        if per > 100:
            per = 100
        return per

    def _get_duration(self, start, end):
        duration = end - start
        per = (duration.total_seconds() / self.duration.total_seconds()) * 100
        if per < 0:
            per = 0
        return per

    def get_measures(self, start, end):
        return (
                self._get_offset(start, end),
                self._get_duration(start, end)
            )


if __name__ == '__main__':
    import ipdb; ipdb.set_trace()