def load_pip_requirements(self, files_map=None, freeze=True):
        if files_map is None:
            files_map = self.default_pip_files
        for group, requirements_txt in files_map.items():
            path = Path(requirements_txt)
            if not path.exists() and group.lower() == "all" and freeze:
                cmd = envoy.run("pip freeze")
                self[group].loads(cmd.std_out)
            elif path.exists():
                self[group].load(path)
def days_till_due(self):
        """
        Returns the number of days till the due date. Returns a negative number
        of days when the due date is in the past.
        Returns 0 when the task has no due date.
        """
        due = self.due_date()
        if due:
            diff = due - date.today()
            return diff.days
        return 0