How to substring a string?

I have a string "MenuItem {Open source}".

How can I get the string Open source from my string?

e.g.

str1 = "MenuItem {Open source}"

perform some actions t开发者_StackOverflowo set string two to be...

print str2  # 'Open source'

How can I acheive this using python or jython?

You can get it with a regular expression.

>>> import re
>>> str1 = "MenuItem {Open source}"
>>> re.search(r'{(.*)}', str1).group(1)
'Open source'

You can also get it by splitting the string on the { and } delimiters (here I use str.rsplit rather than str.split to make sure it splits at the right-most match):

>>> str1.rsplit('{')[1].rsplit('}')[0]
'Open source'

Extracting substrings: Strings in Python can be subscripted just like an array: s[4] = 'a'. Like in IDL, indices can be specified with slice notation i.e., two indices separated by a colon. This will return a substring containing characters index1 through index2-1. Indices can also be negative, in which case they count from the right, i.e. -1 is the last character. Thus substrings can be extracted like

  s = "Go Gators! Come on Gators!"

  x = s[3:9] #x = "Gators"
  x = s[:2] #x = "Go"
  x = s[19:] #x = "Gators!"
  x = s[-7:-2] #x = "Gator"

Therefore in your examplel, you'll need str2 = str1[10:21] = "Open Source".

Of course, that's assuming it's always Open Source and MenuItem...

Instead, you can use find:

int find(sub [,start[,end]])

returns the numeric position of the first occurance of sub in the string. Returns -1 if sub is not found.

  x = s.find("Gator") #x = 3
  x = s.find("gator") #x = -1

So you can use str1.find("{") to get the first brace, and str1.find("}") to get the second.

or in one:

str2 = str1[str1.find("{"):str1.find("}")]

untested code, you may need to add a +1 somewhere, but in theory that should work, or at least get you on the right track ;)

var1 = "MenuItem {Open source}"
var2 = var1.find('{')
var3 = var1.find('}')
ans = var1[var2+1: var3]
print ans

There you are with the string "Open source"!!!