regular expression to detect text in between double curly braces

问题

With regular expression I want to detect text/string between starting and ending double curly braces and it should detect any inner curly braces along with text.

for example:

{{detect this {{and this as well}} text}} but text does not ends here so it should {{not detect this}}.

I have written this regexp

\{\{[\s\S]+\}\}

but this selects the whole string FROM {{detect this.... TO {{not detect this}}

Note: I am using python re for this

回答1:

Pyparsing allows you to define recursive grammars, but has some builtin helpers for common ones like this. See annotated code sample below:

from pyparsing import nestedExpr, ungroup, originalTextFor

# use nestedExpr to define a default expression with left-right nesting markers
nestedText = ungroup(nestedExpr('{{','}}'))

sample = """{{detect this {{and this as well}} text}} but text does not ends here so it should {{not detect this}}."""

# note how reporting the results as a list keeps the nesting of {{ }}'s
print nestedText.parseString(sample).asList()
# prints ['detect', 'this', ['and', 'this', 'as', 'well'], 'text']

# if you just want the string itself, wrap with 'originalTextFor'
print originalTextFor(nestedText).parseString(sample)[0]
# prints {{detect this {{and this as well}} text}}

回答2:

First of all {{[\s\S]+}} is (almost) the same as {{.+}}. Reason: \s contains all spaces and \S contains everything that is not a space. I would generally avoid the upper case character classes in [], it will mostly cause confusion.

Secondly: I think I am on board with thefourtheye, I cannot quickly think of a RegEx to solve your problem.

来源：https://stackoverflow.com/questions/20936622/regular-expression-to-detect-text-in-between-double-curly-braces

标签

python

regex

string