base.py 文件源码

def subtype(self, implicitTag=None, explicitTag=None, subtypeSpec=None,
                sizeSpec=None, cloneValueFlag=None):
        """Create a copy of a |ASN.1| type or object.

        Any parameters to the *subtype()* method will be added to the corresponding
        properties of the |ASN.1| object.

        Parameters
        ----------
        tagSet: :py:class:`~pyasn1.type.tag.TagSet`
            Object representing non-default ASN.1 tag(s)

        subtypeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
            Object representing non-default ASN.1 subtype constraint(s)

        sizeSpec: :py:class:`~pyasn1.type.constraint.ConstraintsIntersection`
            Object representing non-default ASN.1 size constraint(s)

        Returns
        -------
        :
            new instance of |ASN.1| type/value

        """
        if implicitTag is not None:
            tagSet = self._tagSet.tagImplicitly(implicitTag)
        elif explicitTag is not None:
            tagSet = self._tagSet.tagExplicitly(explicitTag)
        else:
            tagSet = self._tagSet
        if subtypeSpec is None:
            subtypeSpec = self._subtypeSpec
        else:
            subtypeSpec = self._subtypeSpec + subtypeSpec
        if sizeSpec is None:
            sizeSpec = self._sizeSpec
        else:
            sizeSpec = sizeSpec + self._sizeSpec
        r = self.__class__(self._componentType, tagSet, subtypeSpec, sizeSpec)
        if cloneValueFlag:
            self._cloneComponentValues(r, cloneValueFlag)
        return r