parser.py 文件源码

def __init__(self, code=None, text=None, filename=None):
        if code:
            self.code = code
            self.text = text
        else:
            if not text:
                assert filename, "If no code or text, need a filename"
                sourcef = open_source(filename)
                try:
                    text = sourcef.read()
                finally:
                    sourcef.close()
            self.text = text

            try:
                # Python 2.3 and 2.4 don't like partial last lines, so be sure
                # the text ends nicely for them.
                self.code = compile(text + '\n', filename, "exec")
            except SyntaxError:
                _, synerr, _ = sys.exc_info()
                raise NotPython(
                    "Couldn't parse '%s' as Python source: '%s' at line %d" %
                        (filename, synerr.msg, synerr.lineno)
                    )

        # Alternative Python implementations don't always provide all the
        # attributes on code objects that we need to do the analysis.
        for attr in ['co_lnotab', 'co_firstlineno', 'co_consts', 'co_code']:
            if not hasattr(self.code, attr):
                raise CoverageException(
                    "This implementation of Python doesn't support code "
                    "analysis.\n"
                    "Run coverage.py under CPython for this command."
                    )