Freelance Automation: Streamlining Client Billing with API Integration

For the past 8 years, I've been working remotely on contract jobs. For clients who pay by the hour, I need to send invoices every two weeks. I tried various invoicing applications before eventually settling on Google Docs.

Then I discovered Wunderlist, a nice to-do list application. I created Shopping and TODO lists and began using it daily. It quickly became a habit for me to record tasks there. I realized it would be perfect for tracking my billable hours as well.

I use the following format for tracking time in tasks:

<hours> hours TASK-1
<minutes> minutes TASK-2
<days> days TASK-3

After a month of tracking my time this way, I wanted to download this data and calculate the hours I'd spent during the month. So I created a script to generate a CSV report of my hours.

import wunderpy2

from dateutil import parser
from datetime import date
from csv import writer


ACCESS_TOKEN = '<WUNDERLIST_ACCESS_TOKEN>'
CLIENT_ID = '<WUNDERLIST_CLIENT_ID>'
PROJECT_BOARD = 'LIST_TITLE'
HOUR_RATE = 1


def __build_hour(task):
    '''
    Parses task titles in formats like:
        dict(title='1 hour CORE-1234')
        dict(title='5 hours CORE-4321')
        dict(title='1 minute CORE-1234')
    '''
    columns = task['title'].strip().split(' ')
    time, measure, task_id = columns
    if measure == 'hour' or measure == 'hours':
        hours = float(time)
    elif measure == 'minute' or measure == 'minutes':
        hours = float(time) / 60
    elif measure == 'day' or measure == 'days':
        hours = 24 * float(time)
    else:
        raise ValueError('Unknown time measure in task title: ' + task['title'])

    return dict(
        task_id=task_id,
        created_at=parser.parse(task['created_at']),
        hours=hours)


def __main__():
    api = wunderpy2.WunderApi()
    client = api.get_client(ACCESS_TOKEN, CLIENT_ID)
    board = [l for l in client.get_lists() if l['title'] == PROJECT_BOARD][0]
    active_tasks = [t for t in client.get_tasks(board['id']) if not t['completed']]
    report = [__build_hour(task) for task in active_tasks]

    estimated_earnings = sum([task['hours'] for task in report]) * HOUR_RATE
    print(estimated_earnings)

    with open(f"report-{date.today()}.csv", 'w+') as f:
        w = writer(f)
        rows = [[task['task_id'], task['hours'], task['created_at'].date()]
                for task in report]
        w.writerows(rows)

    for task in active_tasks:
        client.update_task(task['id'], task['revision'], completed=True)

    # TODO: make monthly output report to pdf file based on created_at field.


if __name__ == '__main__':
    __main__()