parser.py revision 83760d213fb3bec7b4117d266fcfbf6fe2ba14ab 
1# Copyright (C) 2001-2006 Python Software Foundation
2# Author: Barry Warsaw, Thomas Wouters, Anthony Baxter
3# Contact: email-sig@python.org
4
5"""A parser of RFC 2822 and MIME email messages."""
6
7__all__ = ['Parser', 'HeaderParser']
8
9import warnings
10from cStringIO import StringIO
11
12from email.feedparser import FeedParser
13from email.message import Message
14
15
16
17class Parser:
18    def __init__(self, *args, **kws):
19        """Parser of RFC 2822 and MIME email messages.
20
21        Creates an in-memory object tree representing the email message, which
22        can then be manipulated and turned over to a Generator to return the
23        textual representation of the message.
24
25        The string must be formatted as a block of RFC 2822 headers and header
26        continuation lines, optionally preceeded by a `Unix-from' header.  The
27        header block is terminated either by the end of the string or by a
28        blank line.
29
30        _class is the class to instantiate for new message objects when they
31        must be created.  This class must have a constructor that can take
32        zero arguments.  Default is Message.Message.
33        """
34        if len(args) >= 1:
35            if '_class' in kws:
36                raise TypeError("Multiple values for keyword arg '_class'")
37            kws['_class'] = args[0]
38        if len(args) == 2:
39            if 'strict' in kws:
40                raise TypeError("Multiple values for keyword arg 'strict'")
41            kws['strict'] = args[1]
42        if len(args) > 2:
43            raise TypeError('Too many arguments')
44        if '_class' in kws:
45            self._class = kws['_class']
46            del kws['_class']
47        else:
48            self._class = Message
49        if 'strict' in kws:
50            warnings.warn("'strict' argument is deprecated (and ignored)",
51                          DeprecationWarning, 2)
52            del kws['strict']
53        if kws:
54            raise TypeError('Unexpected keyword arguments')
55
56    def parse(self, fp, headersonly=False):
57        """Create a message structure from the data in a file.
58
59        Reads all the data from the file and returns the root of the message
60        structure.  Optional headersonly is a flag specifying whether to stop
61        parsing after reading the headers or not.  The default is False,
62        meaning it parses the entire contents of the file.
63        """
64        feedparser = FeedParser(self._class)
65        if headersonly:
66            feedparser._set_headersonly()
67        while True:
68            data = fp.read(8192)
69            if not data:
70                break
71            feedparser.feed(data)
72        return feedparser.close()
73
74    def parsestr(self, text, headersonly=False):
75        """Create a message structure from a string.
76
77        Returns the root of the message structure.  Optional headersonly is a
78        flag specifying whether to stop parsing after reading the headers or
79        not.  The default is False, meaning it parses the entire contents of
80        the file.
81        """
82        return self.parse(StringIO(text), headersonly=headersonly)
83
84
85
86class HeaderParser(Parser):
87    def parse(self, fp, headersonly=True):
88        return Parser.parse(self, fp, True)
89
90    def parsestr(self, text, headersonly=True):
91        return Parser.parsestr(self, text, True)
92