cloudpickle.py 文件源码

def extract_code_globals(co):
        """
        Find all globals names read or written to by codeblock co
        """
        code = co.co_code
        if not PY3:
            code = [ord(c) for c in code]
        names = co.co_names
        out_names = set()

        n = len(code)
        i = 0
        extended_arg = 0
        while i < n:
            op = code[i]

            i += 1
            if op >= HAVE_ARGUMENT:
                oparg = code[i] + code[i+1] * 256 + extended_arg
                extended_arg = 0
                i += 2
                if op == EXTENDED_ARG:
                    extended_arg = oparg*65536
                if op in GLOBAL_OPS:
                    out_names.add(names[oparg])

        # see if nested function have any global refs
        if co.co_consts:
            for const in co.co_consts:
                if type(const) is types.CodeType:
                    out_names |= CloudPickler.extract_code_globals(const)

        return out_names