cgi.py

mallet是自然语言处理、机器学习领域的一个开源项目。

    filename = None
    list = None
    type = None
    file = None
    type_options = {}
    disposition = None
    disposition_options = {}
    headers = {}

    def __init__(self, name, value):
        """Constructor from field name and value."""
        self.name = name
        self.value = value
        # self.file = StringIO(value)

    def __repr__(self):
        """Return printable representation."""
        return "MiniFieldStorage(%s, %s)" % (`self.name`, `self.value`)


class FieldStorage:

    """Store a sequence of fields, reading multipart/form-data.

    This class provides naming, typing, files stored on disk, and
    more.  At the top level, it is accessible like a dictionary, whose
    keys are the field names.  (Note: None can occur as a field name.)
    The items are either a Python list (if there's multiple values) or
    another FieldStorage or MiniFieldStorage object.  If it's a single
    object, it has the following attributes:

    name: the field name, if specified; otherwise None

    filename: the filename, if specified; otherwise None; this is the
        client side filename, *not* the file name on which it is
        stored (that's a temporary file you don't deal with)

    value: the value as a *string*; for file uploads, this
        transparently reads the file every time you request the value

    file: the file(-like) object from which you can read the data;
        None if the data is stored a simple string

    type: the content-type, or None if not specified

    type_options: dictionary of options specified on the content-type
        line

    disposition: content-disposition, or None if not specified

    disposition_options: dictionary of corresponding options

    headers: a dictionary(-like) object (sometimes rfc822.Message or a
        subclass thereof) containing *all* headers

    The class is subclassable, mostly for the purpose of overriding
    the make_file() method, which is called internally to come up with
    a file open for reading and writing.  This makes it possible to
    override the default choice of storing all files in a temporary
    directory and unlinking them as soon as they have been opened.

    """

    def __init__(self, fp=None, headers=None, outerboundary="",
                 environ=os.environ, keep_blank_values=0, strict_parsing=0):
        """Constructor.  Read multipart/* until last part.

        Arguments, all optional:

        fp              : file pointer; default: sys.stdin
            (not used when the request method is GET)

        headers         : header dictionary-like object; default:
            taken from environ as per CGI spec

        outerboundary   : terminating multipart boundary
            (for internal use only)

        environ         : environment dictionary; default: os.environ

        keep_blank_values: flag indicating whether blank values in
            URL encoded forms should be treated as blank strings.
            A true value indicates that blanks should be retained as
            blank strings.  The default false value indicates that
            blank values are to be ignored and treated as if they were
            not included.

        strict_parsing: flag indicating what to do with parsing errors.
            If false (the default), errors are silently ignored.
            If true, errors raise a ValueError exception.

        """
        method = 'GET'
        self.keep_blank_values = keep_blank_values
        self.strict_parsing = strict_parsing
        if environ.has_key('REQUEST_METHOD'):
            method = environ['REQUEST_METHOD'].upper()
        if method == 'GET' or method == 'HEAD':
            if environ.has_key('QUERY_STRING'):
                qs = environ['QUERY_STRING']
            elif sys.argv[1:]:
                qs = sys.argv[1]
            else:
                qs = ""
            fp = StringIO(qs)
            if headers is None:
                headers = {'content-type':
                           "application/x-www-form-urlencoded"}
        if headers is None:
            headers = {}
            if method == 'POST':
                # Set default content-type for POST to what's traditional
                headers['content-type'] = "application/x-www-form-urlencoded"
            if environ.has_key('CONTENT_TYPE'):
                headers['content-type'] = environ['CONTENT_TYPE']
            if environ.has_key('CONTENT_LENGTH'):
                headers['content-length'] = environ['CONTENT_LENGTH']
        self.fp = fp or sys.stdin
        self.headers = headers
        self.outerboundary = outerboundary

        # Process content-disposition header
        cdisp, pdict = "", {}
        if self.headers.has_key('content-disposition'):
            cdisp, pdict = parse_header(self.headers['content-disposition'])
        self.disposition = cdisp
        self.disposition_options = pdict
        self.name = None
        if pdict.has_key('name'):
            self.name = pdict['name']
        self.filename = None
        if pdict.has_key('filename'):
            self.filename = pdict['filename']

        # Process content-type header
        #
        # Honor any existing content-type header.  But if there is no
        # content-type header, use some sensible defaults.  Assume
        # outerboundary is "" at the outer level, but something non-false
        # inside a multi-part.  The default for an inner part is text/plain,
        # but for an outer part it should be urlencoded.  This should catch
        # bogus clients which erroneously forget to include a content-type
        # header.
        #
        # See below for what we do if there does exist a content-type header,
        # but it happens to be something we don't understand.
        if self.headers.has_key('content-type'):
            ctype, pdict = parse_header(self.headers['content-type'])
        elif self.outerboundary or method != 'POST':
            ctype, pdict = "text/plain", {}
        else:
            ctype, pdict = 'application/x-www-form-urlencoded', {}
        self.type = ctype
        self.type_options = pdict
        self.innerboundary = ""
        if pdict.has_key('boundary'):
            self.innerboundary = pdict['boundary']
        clen = -1
        if self.headers.has_key('content-length'):
            try:
                clen = int(self.headers['content-length'])
            except:
                pass
            if maxlen and clen > maxlen:
                raise ValueError, 'Maximum content length exceeded'
        self.length = clen

        self.list = self.file = None
        self.done = 0
        if ctype == 'application/x-www-form-urlencoded':
            self.read_urlencoded()
        elif ctype[:10] == 'multipart/':
            self.read_multi(environ, keep_blank_values, strict_parsing)
        else:
            self.read_single()

    def __repr__(self):
        """Return a printable representation."""
        return "FieldStorage(%s, %s, %s)" % (
                `self.name`, `self.filename`, `self.value`)

    def __getattr__(self, name):
        if name != 'value':
            raise AttributeError, name
        if self.file:
            self.file.seek(0)
            value = self.file.read()
            self.file.seek(0)
        elif self.list is not None:
            value = self.list
        else:
            value = None
        return value

    def __getitem__(self, key):
        """Dictionary style indexing."""
        if self.list is None:
            raise TypeError, "not indexable"
        found = []
        for item in self.list:
            if item.name == key: found.append(item)
        if not found:
            raise KeyError, key
        if len(found) == 1:
            return found[0]
        else:
            return found

    def getvalue(self, key, default=None):
        """Dictionary style get() method, including 'value' lookup."""
        if self.has_key(key):
            value = self[key]
            if type(value) is type([]):
                return map(lambda v: v.value, value)
            else:
                return value.value
        else:
            return default

    def getfirst(self, key, default=None):
        """ Return the first value received."""
        if self.has_key(key):
            value = self[key]
            if type(value) is type([]):
                return value[0].value
            else:
                return value.value
        else:
            return default

    def getlist(self, key):
        """ Return list of received values."""
        if self.has_key(key):
            value = self[key]
            if type(value) is type([]):
                return map(lambda v: v.value, value)
            else:
                return [value.value]
        else:
            return []

    def keys(self):
        """Dictionary style keys() method."""
        if self.list is None:
            raise TypeError, "not indexable"
        keys = []
        for item in self.list:
            if item.name not in keys: keys.append(item.name)
        return keys

    def has_key(self, key):
        """Dictionary style has_key() method."""
        if self.list is None:
            raise TypeError, "not indexable"
        for item in self.list:
            if item.name == key: return 1
        return 0

    def __len__(self):
        """Dictionary style len(x) support."""
        return len(self.keys())

    def read_urlencoded(self):
        """Internal: read data in query string format."""
        qs = self.fp.read(self.length)
        self.list = list = []
        for key, value in parse_qsl(qs, self.keep_blank_values,
                                    self.strict_parsing):
            list.append(MiniFieldStorage(key, value))
        self.skip_lines()

    FieldStorageClass = None

    def read_multi(self, environ, keep_blank_values, strict_parsing):
        """Internal: read a part that is itself multipart."""
        ib = self.innerboundary
        if not valid_boundary(ib):
            raise ValueError, ('Invalid boundary in multipart form: %s'
                               % `ib`)
        self.list = []
        klass = self.FieldStorageClass or self.__class__
        part = klass(self.fp, {}, ib,
                     environ, keep_blank_values, strict_parsing)
        # Throw first part away
        while not part.done:
            headers = rfc822.Message(self.fp)
            part = klass(self.fp, headers, ib,
                         environ, keep_blank_values, strict_parsing)
            self.list.append(part)
        self.skip_lines()

    def read_single(self):
        """Internal: read an atomic part."""
        if self.length >= 0:
            self.read_binary()
            self.skip_lines()
        else:
            self.read_lines()
        self.file.seek(0)

    bufsize = 8*1024            # I/O buffering size for copy to file

    def read_binary(self):
        """Internal: read binary data."""
        self.file = self.make_file('b')
        todo = self.length
        if todo >= 0:
            while todo > 0:
                data = self.fp.read(min(todo, self.bufsize))
                if not data:
                    self.done = -1
                    break
                self.file.write(data)
                todo = todo - len(data)

    def read_lines(self):
        """Internal: read lines until EOF or outerboundary."""
        self.file = self.__file = StringIO()
        if self.outerboundary:
            self.read_lines_to_outerboundary()
        else:
            self.read_lines_to_eof()

    def __write(self, line):
        if self.__file is not None:
            if self.__file.tell() + len(line) > 1000:
                self.file = self.make_file('')
                self.file.write(self.__file.getvalue())
                self.__file = None
        self.file.write(line)

    def read_lines_to_eof(self):
        """Internal: read lines until EOF."""
        while 1:
            line = self.fp.readline()
            if not line:
                self.done = -1
                break
            self.__write(line)

    def read_lines_to_outerboundary(self):
        """Internal: read lines until outerboundary."""
        next = "--" + self.outerboundary
        last = next + "--"
        delim = ""
        while 1:
            line = self.fp.readline()