[Tutor] Clarification on using regular expression

[Alan Gauld]

On 30/08/2019 11:24, Arulanand Nagarajan (RBEI/EEV51-EC) via Tutor wrote:
> I am currently working on a python script which uses regular expressions for processing some data.
> I have some string as below(each in new line):
> aa1 !=5
> bb1 >=1
> cc1 ==1
> dd2 <= 2
> e3 <2
> >From this string, I want to get a list of all the labels that are before the comparison operator and another list that contains the values after the comparison operator.
> That is
> list1 = ['aa1','bb1','cc1','dd2','e3']
> list2 = ['5','1','1','2','2']
> How will I be able to do that?

Without regular expressions hopefully.

Try:

>>> ops = " !=<>+-/|^~"   # modify to contain all your symbols
>>> strings = ["aa1 !=5", "bb1 >=1","cc1 ==1","dd2 <= 2","e3 <2"]

>>> def getValues(string): return (v.lstrip(ops) for v in string.split())

>>> results = [getValues(s) for s in strings]

You could use a regex here but I think the non regex version is easier.

HTH

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Alan G
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