How to search for a substring in a string, but from a certain index onward-CodePudding

I'm not an expert in python and since it's work related i may have to change some variables and info.

So i have a long string from an API request in which I'm looking for the information of users, and to make sure i only have the users info , I use their ID with .find(ID) which show me the index where the ID is in the string ( middle of the user info). After that what i want is to go up the

string and search for the tag that starts the information 
`**<resource>** and down to the tag that end the information ****</resource>**.` 

**id_position = string.find(id)**
**upper = string[:id_position].rfind("<resource>")** to go in reverse order up the string and find the first match , and works fine

but when i use **lower = string[id_position].find("</resource>")**

, instead of going normally from the id position,down till it finds the first match , it actually searches in the entire original string, as in searching from the first position string[0] onwards.

when i print

**string[:id_position]   string[id_position:] == string** ,

it shows it's true, so i'm guessing the find function doesn't help me like i think it should.

So my question is, how can i search for my specific substring after the index of the id ?

I know it's hard to understand but i hope some of you may know what i mean

for reference,the data looks like this

.<resource>
   name=
   ip=
.</resource>

.<resource>
   name2=
   ip2=
</resource>

.<resource>
   name=
   ip2=
.</resource>

CodePudding user response：

Have you tried using find()s optional parameters start and end?

id_position = string.find(id)
upper = string.find("</resource>", id_position)   len("</resource>")
lower = string.rfind("<resource>", 0, id_position)

print(repr(string[lower:upper]))

> '<resource>\n   name2=\n   ip2=\n</resource>'