Accepting inputs to append to list/dictionary depending on whether data is present on both sides of-CodePudding

I'm attempting to create a list (or dictionary, unsure which is more appropriate) which will have values I have input. It will only append inputted values if it follows the correct format, which is two numbers separated by ';;' (123;;091, 101;;451, etc), and then splits the two numbers. How can I do this? newlist = [x.split('::') for x in list if x] is what I've done but the output comes out as [['123', '101'], ['122', '324'], ['090', '089']], which is correct in a sense but if I was to input just 123;; that would have been accepted.

Any help is greatly appreciated.

CodePudding user response：

You can add a check in that list comprehension to replace if x with if len(x.split('::')) == 2. This will only include elements which have values on both sides of your delimiter.

CodePudding user response：

To reject e.g. "789;;abc", use .findall()

import re
from pprint import pp

s = "789;;abc apple 123;;101 banana 122;;324 cherry 090;;089 date"

two_nums_re = re.compile(r"(\d );;(\d )")
pp(two_nums_re.findall(s), width=16)

That produces:

[('123', '101'),
 ('122', '324'),
 ('090', '089')]

You can easily substitute an alternate delimiter if desired.

>>> " ".join(f"{a}::{b}" for a, b in two_nums_re.findall(s))
'123::101 122::324 090::089'