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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _compileRegExp(string, insensitive, minimal):
 """Compile regular expression. Python function, used by C code NOTE minimal flag is not supported here, but supported on PCRE """

        flags = 0
        if insensitive:
            flags = re.IGNORECASE

        string = string.replace('[_[:alnum:]]', '[\\w\\d]') # ad-hoc fix for C++ parser
        string = string.replace('[:digit:]', '\\d')
        string = string.replace('[:blank:]', '\\s')

        try:
            return re.compile(string, flags)
        except (re.error, AssertionError) as ex:
            _logger.warning("Invalid pattern '%s': %s", string, str(ex))
            return None