+++ /dev/null
-
-:mod:`multifile` --- Support for files containing distinct parts
-================================================================
-
-.. module:: multifile
- :synopsis: Support for reading files which contain distinct parts, such as some MIME data.
- :deprecated:
-.. sectionauthor:: Eric S. Raymond <esr@snark.thyrsus.com>
-
-
-.. deprecated:: 2.5
- The :mod:`email` package should be used in preference to the :mod:`multifile`
- module. This module is present only to maintain backward compatibility.
-
-The :class:`MultiFile` object enables you to treat sections of a text file as
-file-like input objects, with ``''`` being returned by :meth:`readline` when a
-given delimiter pattern is encountered. The defaults of this class are designed
-to make it useful for parsing MIME multipart messages, but by subclassing it and
-overriding methods it can be easily adapted for more general use.
-
-
-.. class:: MultiFile(fp[, seekable])
-
- Create a multi-file. You must instantiate this class with an input object
- argument for the :class:`MultiFile` instance to get lines from, such as a file
- object returned by :func:`open`.
-
- :class:`MultiFile` only ever looks at the input object's :meth:`readline`,
- :meth:`seek` and :meth:`tell` methods, and the latter two are only needed if you
- want random access to the individual MIME parts. To use :class:`MultiFile` on a
- non-seekable stream object, set the optional *seekable* argument to false; this
- will prevent using the input object's :meth:`seek` and :meth:`tell` methods.
-
-It will be useful to know that in :class:`MultiFile`'s view of the world, text
-is composed of three kinds of lines: data, section-dividers, and end-markers.
-MultiFile is designed to support parsing of messages that may have multiple
-nested message parts, each with its own pattern for section-divider and
-end-marker lines.
-
-
-.. seealso::
-
- Module :mod:`email`
- Comprehensive email handling package; supersedes the :mod:`multifile` module.
-
-
-.. _multifile-objects:
-
-MultiFile Objects
------------------
-
-A :class:`MultiFile` instance has the following methods:
-
-
-.. method:: MultiFile.readline(str)
-
- Read a line. If the line is data (not a section-divider or end-marker or real
- EOF) return it. If the line matches the most-recently-stacked boundary, return
- ``''`` and set ``self.last`` to 1 or 0 according as the match is or is not an
- end-marker. If the line matches any other stacked boundary, raise an error. On
- encountering end-of-file on the underlying stream object, the method raises
- :exc:`Error` unless all boundaries have been popped.
-
-
-.. method:: MultiFile.readlines(str)
-
- Return all lines remaining in this part as a list of strings.
-
-
-.. method:: MultiFile.read()
-
- Read all lines, up to the next section. Return them as a single (multiline)
- string. Note that this doesn't take a size argument!
-
-
-.. method:: MultiFile.seek(pos[, whence])
-
- Seek. Seek indices are relative to the start of the current section. The *pos*
- and *whence* arguments are interpreted as for a file seek.
-
-
-.. method:: MultiFile.tell()
-
- Return the file position relative to the start of the current section.
-
-
-.. method:: MultiFile.next()
-
- Skip lines to the next section (that is, read lines until a section-divider or
- end-marker has been consumed). Return true if there is such a section, false if
- an end-marker is seen. Re-enable the most-recently-pushed boundary.
-
-
-.. method:: MultiFile.is_data(str)
-
- Return true if *str* is data and false if it might be a section boundary. As
- written, it tests for a prefix other than ``'-``\ ``-'`` at start of line (which
- all MIME boundaries have) but it is declared so it can be overridden in derived
- classes.
-
- Note that this test is used intended as a fast guard for the real boundary
- tests; if it always returns false it will merely slow processing, not cause it
- to fail.
-
-
-.. method:: MultiFile.push(str)
-
- Push a boundary string. When a decorated version of this boundary is found as
- an input line, it will be interpreted as a section-divider or end-marker
- (depending on the decoration, see :rfc:`2045`). All subsequent reads will
- return the empty string to indicate end-of-file, until a call to :meth:`pop`
- removes the boundary a or :meth:`next` call reenables it.
-
- It is possible to push more than one boundary. Encountering the
- most-recently-pushed boundary will return EOF; encountering any other
- boundary will raise an error.
-
-
-.. method:: MultiFile.pop()
-
- Pop a section boundary. This boundary will no longer be interpreted as EOF.
-
-
-.. method:: MultiFile.section_divider(str)
-
- Turn a boundary into a section-divider line. By default, this method
- prepends ``'--'`` (which MIME section boundaries have) but it is declared so
- it can be overridden in derived classes. This method need not append LF or
- CR-LF, as comparison with the result ignores trailing whitespace.
-
-
-.. method:: MultiFile.end_marker(str)
-
- Turn a boundary string into an end-marker line. By default, this method
- prepends ``'--'`` and appends ``'--'`` (like a MIME-multipart end-of-message
- marker) but it is declared so it can be overridden in derived classes. This
- method need not append LF or CR-LF, as comparison with the result ignores
- trailing whitespace.
-
-Finally, :class:`MultiFile` instances have two public instance variables:
-
-
-.. attribute:: MultiFile.level
-
- Nesting depth of the current part.
-
-
-.. attribute:: MultiFile.last
-
- True if the last end-of-file was for an end-of-message marker.
-
-
-.. _multifile-example:
-
-:class:`MultiFile` Example
---------------------------
-
-.. sectionauthor:: Skip Montanaro <skip@pobox.com>
-
-
-::
-
- import mimetools
- import multifile
- import StringIO
-
- def extract_mime_part_matching(stream, mimetype):
- """Return the first element in a multipart MIME message on stream
- matching mimetype."""
-
- msg = mimetools.Message(stream)
- msgtype = msg.gettype()
- params = msg.getplist()
-
- data = StringIO.StringIO()
- if msgtype[:10] == "multipart/":
-
- file = multifile.MultiFile(stream)
- file.push(msg.getparam("boundary"))
- while file.next():
- submsg = mimetools.Message(file)
- try:
- data = StringIO.StringIO()
- mimetools.decode(file, data, submsg.getencoding())
- except ValueError:
- continue
- if submsg.gettype() == mimetype:
- break
- file.pop()
- return data.getvalue()
-
+++ /dev/null
-"""A readline()-style interface to the parts of a multipart message.
-
-The MultiFile class makes each part of a multipart message "feel" like
-an ordinary file, as long as you use fp.readline(). Allows recursive
-use, for nested multipart messages. Probably best used together
-with module mimetools.
-
-Suggested use:
-
-real_fp = open(...)
-fp = MultiFile(real_fp)
-
-"read some lines from fp"
-fp.push(separator)
-while 1:
- "read lines from fp until it returns an empty string" (A)
- if not fp.next(): break
-fp.pop()
-"read remaining lines from fp until it returns an empty string"
-
-The latter sequence may be used recursively at (A).
-It is also allowed to use multiple push()...pop() sequences.
-
-If seekable is given as 0, the class code will not do the bookkeeping
-it normally attempts in order to make seeks relative to the beginning of the
-current file part. This may be useful when using MultiFile with a non-
-seekable stream object.
-"""
-
-__all__ = ["MultiFile","Error"]
-
-class Error(Exception):
- pass
-
-class MultiFile:
-
- seekable = 0
-
- def __init__(self, fp, seekable=1):
- self.fp = fp
- self.stack = []
- self.level = 0
- self.last = 0
- if seekable:
- self.seekable = 1
- self.start = self.fp.tell()
- self.posstack = []
-
- def tell(self):
- if self.level > 0:
- return self.lastpos
- return self.fp.tell() - self.start
-
- def seek(self, pos, whence=0):
- here = self.tell()
- if whence:
- if whence == 1:
- pos = pos + here
- elif whence == 2:
- if self.level > 0:
- pos = pos + self.lastpos
- else:
- raise Error("can't use whence=2 yet")
- if not 0 <= pos <= here or \
- self.level > 0 and pos > self.lastpos:
- raise Error('bad MultiFile.seek() call')
- self.fp.seek(pos + self.start)
- self.level = 0
- self.last = 0
-
- def readline(self):
- if self.level > 0:
- return ''
- line = self.fp.readline()
- # Real EOF?
- if not line:
- self.level = len(self.stack)
- self.last = (self.level > 0)
- if self.last:
- raise Error('sudden EOF in MultiFile.readline()')
- return ''
- assert self.level == 0
- # Fast check to see if this is just data
- if self.is_data(line):
- return line
- else:
- # Ignore trailing whitespace on marker lines
- marker = line.rstrip()
- # No? OK, try to match a boundary.
- # Return the line (unstripped) if we don't.
- for i, sep in enumerate(reversed(self.stack)):
- if marker == self.section_divider(sep):
- self.last = 0
- break
- elif marker == self.end_marker(sep):
- self.last = 1
- break
- else:
- return line
- # We only get here if we see a section divider or EOM line
- if self.seekable:
- self.lastpos = self.tell() - len(line)
- self.level = i+1
- if self.level > 1:
- raise Error('Missing endmarker in MultiFile.readline()')
- return ''
-
- def readlines(self):
- list = []
- while 1:
- line = self.readline()
- if not line: break
- list.append(line)
- return list
-
- def read(self): # Note: no size argument -- read until EOF only!
- return ''.join(self.readlines())
-
- def next(self):
- while self.readline(): pass
- if self.level > 1 or self.last:
- return 0
- self.level = 0
- self.last = 0
- if self.seekable:
- self.start = self.fp.tell()
- return 1
-
- def push(self, sep):
- if self.level > 0:
- raise Error('bad MultiFile.push() call')
- self.stack.append(sep)
- if self.seekable:
- self.posstack.append(self.start)
- self.start = self.fp.tell()
-
- def pop(self):
- if self.stack == []:
- raise Error('bad MultiFile.pop() call')
- if self.level <= 1:
- self.last = 0
- else:
- abslastpos = self.lastpos + self.start
- self.level = max(0, self.level - 1)
- self.stack.pop()
- if self.seekable:
- self.start = self.posstack.pop()
- if self.level > 0:
- self.lastpos = abslastpos - self.start
-
- def is_data(self, line):
- return line[:2] != '--'
-
- def section_divider(self, str):
- return "--" + str
-
- def end_marker(self, str):
- return "--" + str + "--"
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