Class Parser

Lib/email/parser.py:16–64

class Parser:
    def __init__(self, _class=None, *, policy=compat32):
        """Parser of RFC 5322 and MIME email messages.

        Creates an in-memory object tree representing the email message, which
        can then be manipulated and turned over to a Generator to return the
        textual representation of the message.

        The string must be formatted as a block of RFC 5322 headers and header
        continuation lines, optionally preceded by a 'Unix-from' header.  The
        header block is terminated either by the end of the string or by a
        blank line.

        _class is the class to instantiate for new message objects when they
        must be created.  This class must have a constructor that can take
        zero arguments.  Default is Message.Message.

        The policy keyword specifies a policy object that controls a number of
        aspects of the parser's operation.  The default policy maintains
        backward compatibility.

        """
        self._class = _class
        self.policy = policy

    def parse(self, fp, headersonly=False):
        """Create a message structure from the data in a file.

        Reads all the data from the file and returns the root of the message
        structure.  Optional headersonly is a flag specifying whether to stop
        parsing after reading the headers or not.  The default is False,
        meaning it parses the entire contents of the file.
        """
        feedparser = FeedParser(self._class, policy=self.policy)
        if headersonly:
            feedparser._set_headersonly()
        while data := fp.read(8192):
            feedparser.feed(data)
        return feedparser.close()

    def parsestr(self, text, headersonly=False):
        """Create a message structure from a string.

        Returns the root of the message structure.  Optional headersonly is a
        flag specifying whether to stop parsing after reading the headers or
        not.  The default is False, meaning it parses the entire contents of
        the file.
        """
        return self.parse(StringIO(text), headersonly=headersonly)


class HeaderParser(Parser):