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+--- Thread: Help getting a string out of regex (/thread-31274.html)
Help getting a string out of regex - matt_the_hall - Dec-01-2020
Hello, I am trying to better understand the regular expression module, specifically, how to get it to return a string that I can use elsewhere.
Preface to the code:
This is a script for an open source chat server called "Zulip," utilizing their API. The script is working fine until I get a "not None" response, and then I get the following error:
Error:unning Snoozebot Bot:
The goal here is to have a snooze for messages, similar to the snooze function on Gmail. When you write
@snoozebot a message for a snooze reminder x minutes, hours, days, etc. from now @snoozebot
first replies by echoing back the requested snooze time interval. X time later, it sends a message to the
stream pinging the users in the snooze request. I am thinking of something like @snoozebot snooze for (x) (time)
for [list of users].
INFO:root:starting message handling...
INFO:root:waiting for next message
Traceback (most recent call last):
File "/home/zulip/.local/bin/zulip-run-bot", line 10, in <module>
sys.exit(main())
File "/home/zulip/.local/lib/python3.7/site-packages/zulip_bots/run.py", line 152, in main
bot_name=bot_name
File "/home/zulip/.local/lib/python3.7/site-packages/zulip_bots/lib.py", line 382, in run_message_handler_for_bot
client.call_on_each_event(event_callback, ['message'])
File "/usr/local/lib/python3.7/dist-packages/zulip/__init__.py", line 680, in call_on_each_event
callback(event)
File "/home/zulip/.local/lib/python3.7/site-packages/zulip_bots/lib.py", line 380, in event_callback
handle_message(event['message'], event['flags'])
File "/home/zulip/.local/lib/python3.7/site-packages/zulip_bots/lib.py", line 371, in handle_message
bot_handler=restricted_client
File "/home/zulip/python-zulip-api/zulip_bots/zulip_bots/bots/snoozebot/snoozebot.py", line 31, in handle_message
match.join(y)
AttributeError: 'list' object has no attribute 'join'Here's the script:
from typing import Any, Dict
import re
class SnoozeBotHandler:
def usage(self) -> str:
return '''
The goal here is to have a snooze for messages, similar to the snooze function on Gmail. When you write
@snoozebot a message for a snooze reminder x minutes, hours, days, etc. from now @snoozebot
first replies by echoing back the requested snooze time interval. X time later, it sends a message to the
stream pinging the users in the snooze request. I am thinking of something like @snoozebot snooze for (x) (time)
for [list of users].
'''
def handle_message(self, message: Dict[str, Any], bot_handler: Any) -> None:
# setting up regex pattern here
# hopefully this pattern object will work for any iteration of "snooze for x days/weeks/months...will have to test.
pattern1 = re.compile(r'(\bday\b)', re.IGNORECASE)
match = pattern1.findall(message['content'])
# message handling
if message['content'] == '':
bot_response = "Please specify the **snooze interval** and **users** to be reminded. For help, message me with 'help.'"
bot_handler.send_reply(message, bot_response)
elif message['content'] == 'help':
bot_handler.send_reply(message, self.usage())
else:
if pattern1.search(message['content']) != None:
y = ["Ok, I'll remind you in "]
match.join(y)
bot_handler.send_reply(message, y)
emoji_name = 'alarm clock'
bot_handler.react(message, emoji_name)
else:
bot_handler.send_reply(message, "Oops, that won't work. Message me with 'help' for help on how to use me.")
return
handler_class = SnoozeBotHandler
RE: Help getting a string out of regex - bowlofred - Dec-01-2020
You don't join things into a list. If you have one element you want to add, you
.append() it. If you have another list you want to tack onto the end you .extend() it.re.findall should return a list (of possibly identical items), so extending is I guess what you want...
match = ["match1", "match2"] y = ["item1"] y.extend(match) print(y)
Output:['item1', 'match1', 'match2']RE: Help getting a string out of regex - matt_the_hall - Dec-01-2020
@bowlofred, Thanks so much, that did get me closer to what I am aiming for. I am, however, trying to get a final output that is all one string, like this: Ok, I'll remind you in 4 days. I haven't set up the regular expression to take # day(s), yet; I am just using 'day' for simplicity's sake.
In any case, perhaps you can help me understand the output I am getting, now. Below is the raw output in the terminal (using print functions to try and help me understand what my code is doing):
Error:INFO:root:starting message handling...
INFO:root:waiting for next message
day
['day']
Ok, I'll remind you in
INFO:root:waiting for next message y = "Ok, I'll remind you in "
x = str(match[0])
print(x)
print(match)
y.join(x)
print(y)
bot_handler.send_reply(message, y)So, I'm a little confused why y.join(x) is not tacking 'day' onto the end of 'Ok, I'll remind you in '. Am I correct in understanding that x = str(match[0]) converts the 0th element of the list match to a string object equal to x? if so, why do I get 'Ok, I'll remind you in ' for print(y)?
RE: Help getting a string out of regex - bowlofred - Dec-01-2020
join() is an operator on a string, and it doesn't modify anything. It returns a new string.Since you're not assigning the result of the join, the result is thrown away and y remains the same.
y = "Hello, world!" l = ["one", "two", "three"] y.join(l) print(y) # no change y = y.join(l) # assigns the change back to y print(y) # now the change is seen
Output:Hello, world!
oneHello, world!twoHello, world!threejoin() at all. It sounds like you just want to concatenate two strings. You can do that with a plus symbol if you have two strings.
RE: Help getting a string out of regex - matt_the_hall - Dec-02-2020
It works! Thank you so much! Gosh, I read so many tutorials and threads on this, and no one explained it so simply and clearly. Would you mind suggesting a book or two that you think might help me progress in my Python skills?