[R] A question on regular expression

[Christofer Bogaso]

Awesome, thanks!

On Fri, Sep 13, 2019 at 12:19 AM Bert Gunter <bgunter.4567 using gmail.com> wrote:
>
>
> You can't use the same regex for str_extract_all as I used for sub (or gsub, which is what is required here)! If you do this sort of thing a lot, you *must* learn more about regex's.
>
> Anyway, this will do what you want I think:
>
> z <- paste("ab{cd$ }ed", "ab{cad$ }ed", collapse = " ")  ## just for readability
>
> > str_extract_all(z,"\\{[^}]*\\}")
> [[1]]
> [1] "{cd$ }"  "{cad$ }"
>
> Cheers,
> Bert
>
> On Thu, Sep 12, 2019 at 10:12 AM Christofer Bogaso <bogaso.christofer using gmail.com> wrote:
>>
>> Thanks Bert,
>>
>> This works, but if in my text there are more than one patterns then
>> fails to generate desired result.
>>
>> library(stringr)
>> str_extract_all(paste("ab{cd$ }ed", "ab{cad$ }ed", collapse = " "),
>> ".*(\\{.*\\}).*")
>>
>> This generates below -
>>
>> [[1]]
>>
>> [1] "ab{cd$ }ed ab{cad$ }ed"
>>
>> I was expecting I would get a vector of length 2 with desired pattern.
>>
>> Where did I make any mistake?
>>
>> Thanks,
>>
>> On Thu, Sep 12, 2019 at 10:29 PM Bert Gunter <bgunter.4567 using gmail.com> wrote:
>> >
>> > > sub(".*(\\{.*\\}).*", "\\1","ab{cd$ }ed")
>> > [1] "{cd$ }"
>> >
>> > Use ".+" instead of ".*" within the {} if you don't want to return empty {}'s.
>> >
>> > You might wish to use the stringr package for string matching and manipulation, as it provides a more user friendly and consistent interface to these tasks.
>> >
>> >
>> > Bert Gunter
>> >
>> > "The trouble with having an open mind is that people keep coming along and sticking things into it."
>> > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>> >
>> >
>> > On Thu, Sep 12, 2019 at 9:31 AM Christofer Bogaso <bogaso.christofer using gmail.com> wrote:
>> >>
>> >> Hi,
>> >>
>> >> I am wondering on what is the correct way to select a pattern which goes as -
>> >>
>> >> {"(any character with any length)"}
>> >>
>> >> The expressions " {" " and " "} " both are included in the pattern.
>> >>
>> >> For example, the lookup of the above pattern in the text "
>> >> {"asaf455%"}57573blabla " will result in {"asaf455%"}
>> >>
>> >> Any help will be highly appreciated.
>> >>
>> >> Thanks,
>> >>
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