Method replace_header

Lib/email/message.py:589–602

Replace a header. Replace the first matching header found in the message, retaining header order and case. If no matching header was found, a KeyError is raised.

(self, _name, _value)

        self[_name] = SEMISPACE.join(parts)

    def replace_header(self, _name, _value):
        """Replace a header.

        Replace the first matching header found in the message, retaining
        header order and case.  If no matching header was found, a KeyError is
        raised.
        """
        _name = _name.lower()
        for i, (k, v) in zip(range(len(self._headers)), self._headers):
            if k.lower() == _name:
                self._headers[i] = self.policy.header_store_parse(k, _value)
                break
        else:
            raise KeyError(_name)

    #
    # Use these three methods instead of the three above.