Python Forum

Hi guys,
Hoping somebody can help me here. I have a list of email messages and their UID's. I need to use re.findall() to select just the UID from the list.

The format of the input is:

b' +OK 1 19
b' +OK 2 22
b' +OK 3 25
etc.

Now, I can use this re to return the below format,

messageUID = re.findall(r'\d+ \d+',messageUID,0)[0]

{msgNum UID}:

However, I'm trying to retrieve just the UID (19, 22, 25, 28... etc)
Which is the 2nd occurrence of r' \d+'

How can I do this?

First of all, if your input is as regular as you show, I would not use the regex and just split() it.

uid = messageUID.split()[-1]

But if it's useful for other reasons, use parenthesis to change the second digit block into a group. Then the 0th element will refer to that group.

>>> re.findall(r'\d+ \d+',' +OK 1 19',0)[0]
'1 19'
>>> re.findall(r'\d+ (\d+)',' +OK 1 19',0)[0]
'19'

(Oct-13-2020, 03:55 PM)bowlofred Wrote: [ -> ]First of all, if your input is as regular as you show, I would not use the regex and just split() it.
uid = messageUID.split()[-1]
But if it's useful for other reasons, use parenthesis to change the second digit block into a group. Then the 0th element will refer to that group.
>>> re.findall(r'\d+ \d+',' +OK 1 19',0)[0]
'1 19'
>>> re.findall(r'\d+ (\d+)',' +OK 1 19',0)[0]
'19'
Thanks for the suggestion.
I just found that selecting the second item from the list like this, also gives me what I want. I will try your suggestions if I continue to run into trouble!
messageUID=re.findall(r'\d+',messageUID,0)[1]

t4keheart

bowlofred

t4keheart