VariableLength

class ccsdspy.VariableLength(fields)

Bases: _BasePacket

Define a variable length packet to decode binary data.

Variable length packets are packets which have a different length each time. Each variable length packet should have a single PacketArray with the array_shape=’expand’, which will grow to fill the packet.

Please note that while this class is able to parse fixed length packets, it is much slower. Use the FixedLength class instead.

Rules for variable length packets:

• Do provide only one one expanding PacketArray with array_shape=’expand’.

• Do not specify the primary header fields manually

• Do not specify explicit bit_offsets (they will be computed

automatically)

Parameters:

fieldslist of PacketField or PacketArray

Layout of packet fields contained in the definition. No more than one field should have array_shape=”expand”. The field must have no bit_offset’s. Do not include the primary header fields.

Raises:

ValueError

one or more of the arguments are invalid, or do not follow the specified rules.

Methods Summary

load(file[, include_primary_header])

Decode a file-like object containing a sequence of these packets.

Methods Documentation

load(file, include_primary_header=False)

Decode a file-like object containing a sequence of these packets.

Parameters:

filestr

Path to file on the local file system, or file-like object

include_primary_headerbool

If True, provides the primary header in the output

Returns:

field_arraysdict, string to NumPy array

dictionary mapping field names to NumPy arrays, with key order matching the order of fields in the packet.