Simple slack bot in python

Question

I wrote a simple slack bot, which is able to save links (command: "save name link") and print them (command: "get name"). Optionally, a delay in minutes and seconds can be specified (command: "get name XmXs"). I would appreciate any feedback.

import os
import re
from time import sleep
from threading import Thread
from slackclient import SlackClient
BOT_NAME = 'klausbot'
BOT_ID = ''
slack_client = SlackClient(os.environ['SLACK_BOT_TOKEN'])
links = {}
save_pattern = re.compile('^save\s(?P<name>[a-zA-Z]+)\s(?P<link>\S+)$')
get_pattern = re.compile('^get\s(?P<name>[a-zA-Z]+)\s?((?P<minutes>\d+)m)?\s?((?P<seconds>\d+)s)?$')
def get_bot_id():
 api_call = slack_client.api_call('users.list')
 if api_call.get('ok'):
 users = api_call.get('members')
 for user in users:
 if 'name' in user and user.get('name') == BOT_NAME:
 global BOT_ID
 BOT_ID = '<@{}>'.format(user.get('id'))
def parse_message(message):
 text = message['text']
 if text.startswith(BOT_ID):
 text = text.split(BOT_ID)[1].strip().lower()
 if save_pattern.match(text):
 handle_save_command(message, save_pattern.match(text))
 elif get_pattern.match(text):
 handle_get_command(message, get_pattern.match(text))
 else:
 post_message('Command not found', message['channel'])
def handle_save_command(message, match):
 name = match.group('name')
 link = match.group('link')
 links[name] = link
 response = '{} saved to {}'.format(link, name)
 post_message(response, message['channel'])
def calculate_time(match):
 minutes = match.group('minutes') or 0
 seconds = match.group('seconds') or 0
 return int(minutes) * 60 + int(seconds)
def handle_get_command(message, match):
 name = match.group('name')
 if name not in links:
 error_message = '{} not found'.format(name)
 post_message(error_message, message['channel'])
 else:
 sleep_time = calculate_time(match)
 sleep(sleep_time)
 post_message(links[name], message['channel'])
def handle_messages_read(messages):
 if messages and len(messages) > 0:
 for message in messages:
 if message and 'text' in message:
 parse_message(message)
def post_message(message, channel='#general'):
 slack_client.api_call(
 'chat.postMessage',
 channel=channel,
 text=message,
 as_user=True
 )
if __name__ == '__main__':
 if slack_client.rtm_connect():
 print('KlausBot started and running')
 get_bot_id()
 while True:
 messages = slack_client.rtm_read()
 handle_message_thread = Thread(target=handle_messages_read, args=(messages,))
 handle_message_thread.start()
 sleep(0.1)
 else:
 print('Could not connect')

Answer 1

In general this code looks pretty good. I do have a couple of small pythonism comments:

dict.get() returns None if key not present:

This:

if 'name' in user and user.get('name') == BOT_NAME:

Can simply be this:

if user.get('name') == BOT_NAME:

... since dict.get() will return None if the key is not present and I presume BOT_NAME will never be None.

Iterating over 0 length item:

This:

if messages and len(messages) > 0:
 for message in messages:

Can simply be this:

if messages:
 for message in messages:

... since the for loop will not have anything to do if the length is zero.

Also, I am not sure what this if is testing for:

if messages:
 for message in messages:

If guarding against None, then it would be more pythonic as:

if messages is not None:
 for message in messages:

And if the check is a surrogate length check, then it isn't necessary at all, and the if could be removed.