Returns a list of hour/min in which snapshopts are present

def list_snapshots_hours(path, cam_id, day):
    """Returns a list of hour/min in which snapshopts are present"""
    screenshoots_path = path+"/"+str(cam_id)+"/"+day
    if os.path.exists(screenshoots_path):
        hours = []
        for hour_dir in sorted(os.listdir(screenshoots_path)):
            hrm = datetime.datetime.strptime(hour_dir, "%H%M").strftime('%H:%M')
            hours.append((hrm, hour_dir))
        return hours
    else:
        return []