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(python2.1-lib.info)Unpacker Objects

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Unpacker Objects
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The `Unpacker' class offers the following methods:

`reset(data)'
     Resets the string buffer with the given DATA.

`get_position()'
     Returns the current unpack position in the data buffer.

`set_position(position)'
     Sets the data buffer unpack position to POSITION.  You should be
     careful about using `get_position()' and `set_position()'.

`get_buffer()'
     Returns the current unpack data buffer as a string.

`done()'
     Indicates unpack completion.  Raises an `Error' exception if all
     of the data has not been unpacked.

In addition, every data type that can be packed with a `Packer', can be
unpacked with an `Unpacker'.  Unpacking methods are of the form
`unpack_TYPE()', and take no arguments.  They return the unpacked
object.

`unpack_float()'
     Unpacks a single-precision floating point number.

`unpack_double()'
     Unpacks a double-precision floating point number, similarly to
     `unpack_float()'.

In addition, the following methods unpack strings, bytes, and opaque
data:

`unpack_fstring(n)'
     Unpacks and returns a fixed length string.  N is the number of
     characters expected.  Padding with null bytes to guaranteed 4 byte
     alignment is assumed.

`unpack_fopaque(n)'
     Unpacks and returns a fixed length opaque data stream, similarly to
     `unpack_fstring()'.

`unpack_string()'
     Unpacks and returns a variable length string.  The length of the
     string is first unpacked as an unsigned integer, then the string
     data is unpacked with `unpack_fstring()'.

`unpack_opaque()'
     Unpacks and returns a variable length opaque data string,
     similarly to `unpack_string()'.

`unpack_bytes()'
     Unpacks and returns a variable length byte stream, similarly to
     `unpack_string()'.

The following methods support unpacking arrays and lists:

`unpack_list(unpack_item)'
     Unpacks and returns a list of homogeneous items.  The list is
     unpacked one element at a time by first unpacking an unsigned
     integer flag.  If the flag is `1', then the item is unpacked and
     appended to the list.  A flag of `0' indicates the end of the
     list.  UNPACK_ITEM is the function that is called to unpack the
     items.

`unpack_farray(n, unpack_item)'
     Unpacks and returns (as a list) a fixed length array of homogeneous
     items.  N is number of list elements to expect in the buffer.  As
     above, UNPACK_ITEM is the function used to unpack each element.

`unpack_array(unpack_item)'
     Unpacks and returns a variable length LIST of homogeneous items.
     First, the length of the list is unpacked as an unsigned integer,
     then each element is unpacked as in `unpack_farray()' above.