kitty.model.low_level.encoder module¶

Encoders are used for encoding fields and containers. The encoders are passed as an argument to the fields/container, during the field rendering, the encoder’s encode method is called.

There are four families of encoders:

String Encoders:
Bits Encoders:	Used to encode fields/containers that their value is of type Bits (Container, ForEach etc.)
	Used to encode fields that their value is of type str (String, Delimiter, RandomBytes etc.)
BitField Encoders:
	Used to encode fields that inherit from BitField or contain BitField (UInt8, Size, Checksum etc.) Those encoders are also refferred to as Int Encoders.
FloatingPoint Encoders:
	Used to encode fields that inherit from FloatingPoint field (Float, Double) Those encoders are also refferred to as Float Encoders

class kitty.model.low_level.encoder.BitFieldAsciiEncoder(fmt)[source]¶

Bases: kitty.model.low_level.encoder.BitFieldEncoder

Encode int as ascii

__init__(fmt)[source]¶

Parameters:	fmt – format for encoding (from BitFieldAsciiEncoder.formats)

encode(value, length, signed)[source]¶

formats = ['%d', '%x', '%X', '%#x', '%#X']¶

class kitty.model.low_level.encoder.BitFieldBinEncoder(mode)[source]¶

Bases: kitty.model.low_level.encoder.BitFieldEncoder

Encode int as binary

__init__(mode)[source]¶

Parameters:	mode (str) – mode of binary encoding. ‘le’ for little endian, ‘be’ for big endian, ‘’ for non-byte aligned

encode(value, length, signed)[source]¶

Parameters:	value – value to encode length – length of value in bits signed – is value signed

class kitty.model.low_level.encoder.BitFieldEncoder[source]¶

Bases: object

Base encoder class for BitField values

Singleton Name	Encoding	Class
ENC_INT_BIN	Encode as binary bits	BitFieldBinEncoder
ENC_INT_LE	Encode as a little endian binary bits
ENC_INT_BE	Encode as a big endian binary bits
ENC_INT_DEC	Encode as a decimal value	BitFieldAsciiEncoder
ENC_INT_HEX	Encode as a hex value
ENC_INT_HEX_UPPER	Encode as an upper case hex value
ENC_INT_DEFAULT	Same as ENC_INT_BIN	BitFieldBinEncoder

encode(value, length, signed)[source]¶

Parameters:	value (`int`) – value to encode length (`int`) – length of value in bits signed (`boolean`) – is value signed

class kitty.model.low_level.encoder.BitFieldMultiByteEncoder(mode='be')[source]¶

Bases: kitty.model.low_level.encoder.BitFieldEncoder

Encode int as multi-byte (used in WBXML format)

__init__(mode='be')[source]¶

Parameters:	mode (str) – mode of binary encoding. ‘le’ for little endian, ‘be’ for big endian, ‘’ for non-byte aligned

encode(value, length, signed)[source]¶

Parameters:	value – value to encode length – length of value in bits signed – is value signed

class kitty.model.low_level.encoder.BitsEncoder[source]¶

Bases: object

Base encoder class for Bits values

The Bits encoders encode function receives a Bits object as an argument and returns an encoded Bits object.

Singleton Name	Encoding	Class
ENC_BITS_NONE	None, returns the same value received	BitsEncoder
ENC_BITS_BYTE_ALIGNED	Appends bits to the received object to make it byte aligned	ByteAlignedBitsEncoder
ENC_BITS_REVERSE	Reverse the order of bits	ReverseBitsEncoder
ENC_BITS_BASE64	Encode a Byte aligned bits in base64	StrEncoderWrapper
ENC_BITS_BASE64_NO_NL	Encode a Byte aligned bits in base64, but removes the new line from the end
ENC_BITS_UTF8	Encode a Byte aligned bits in UTF-8
ENC_BITS_HEX	Encode a Byte aligned bits in hex
ENC_BITS_DEFAULT	Same as ENC_BITS_NONE

encode(value)[source]¶

Parameters:	value (Bits) – value to encode

class kitty.model.low_level.encoder.BitsFuncEncoder(func)[source]¶

Bases: kitty.model.low_level.encoder.BitsEncoder

Encode bits using a given function

__init__(func)[source]¶

Parameters:	func – encoder function(Bits)->Bits

encode(value)[source]¶

class kitty.model.low_level.encoder.ByteAlignedBitsEncoder[source]¶

Bases: kitty.model.low_level.encoder.BitsEncoder

Stuff bits for byte alignment

encode(value)[source]¶

Parameters:	value – value to encode

class kitty.model.low_level.encoder.FloatAsciiEncoder(fmt)[source]¶

Bases: kitty.model.low_level.encoder.FloatEncoder

Encode a floating point number in ascii as described by IEEE 754 (decimal*)

__init__(fmt)[source]¶

Parameters:	fmt (str) – format of ascii encoding (see floating point encoding in string docs.)

encode(value)[source]¶

Parameters:	value – value to encode

class kitty.model.low_level.encoder.FloatBinEncoder(fmt)[source]¶

Bases: kitty.model.low_level.encoder.FloatEncoder

Encode a floating point number in binary format as described by IEEE 754 (binary32 and binary64)

__init__(fmt)[source]¶

Parameters:	fmt (str) – format of binary encoding (see floating point encoding in struct docs.)

encode(value)[source]¶

Parameters:	value – value to encode

class kitty.model.low_level.encoder.FloatEncoder[source]¶

Bases: object

Base encoder class for FloatingPoint values

Singleton Name	Encoding	Class
ENC_FLT_LE	Encode as a little endian 32 bit	`FloatBinEncoder`
ENC_FLT_BE	Encode as a big endian 32 bit
ENC_DBL_LE	Encode as a little endian 64 bit
ENC_DBL_BE	Encode as a big endian 64 bit
ENC_FLT_FP	Fixed point	`FloatAsciiEncoder`
ENC_FLT_EXP	Exponent notation
ENC_FLT_EXP_UPPER	Exponent notation, with upper case E
ENC_FLT_GEN	General format
ENC_FLT_GEN_UPPER	General format, with upper case
ENC_FLT_DEFAULT	Same as ENC_FLT_BE	`FloatBinEncoder`

encode(value)[source]¶

Parameters:	value (`float`) – value to encode
Return type:	`Bits`
Returns:	encoded value in bits

class kitty.model.low_level.encoder.ReverseBitsEncoder[source]¶

Bases: kitty.model.low_level.encoder.BitsEncoder

Reverse the order of bits

encode(value)[source]¶

Parameters:	value – value to encode

class kitty.model.low_level.encoder.StrBase64NoNewLineEncoder[source]¶

Bases: kitty.model.low_level.encoder.StrEncoder

Encode the string as base64, but without the new line at the end

encode(value)[source]¶

Parameters:	value – value to encode

class kitty.model.low_level.encoder.StrEncodeEncoder(encoding)[source]¶

Bases: kitty.model.low_level.encoder.StrEncoder

Encode the string using str.encode function

__init__(encoding)[source]¶

Parameters:	encoding (`str`) – encoding to be used, should be a valid argument for str.encode

encode(value)[source]¶

Parameters:	value – value to encode

class kitty.model.low_level.encoder.StrEncoder[source]¶

Bases: object

Base encoder class for str values The String encoders encode function receives a str object as an argument and returns an encoded Bits object.

Singleton Name	Encoding	Class
ENC_STR_UTF8	Encode the str in UTF-8	StrEncodeEncoder
ENC_STR_HEX	Encode the str in hex
ENC_STR_BASE64	Encode the str in base64
ENC_STR_BASE64_NO_NL	Encode the str in base64 but remove the new line from the end	StrBase64NoNewLineEncoder
ENC_STR_DEFAULT	Do nothing, just convert the str to Bits object	StrEncoder

encode(value)[source]¶

Parameters:	value (`str`) – value to encode

class kitty.model.low_level.encoder.StrEncoderWrapper(encoder)[source]¶

Bases: kitty.model.low_level.encoder.ByteAlignedBitsEncoder

Encode the data using str.encode function

__init__(encoder)[source]¶

Parameters:	encoding (StrEncoder) – encoder to wrap

encode(value)[source]¶

Parameters:	value – value to encode

class kitty.model.low_level.encoder.StrFuncEncoder(func)[source]¶

Bases: kitty.model.low_level.encoder.StrEncoder

Encode string using a given function

__init__(func)[source]¶

Parameters:	func – encoder function(str)->str

encode(value)[source]¶

class kitty.model.low_level.encoder.StrNullTerminatedEncoder[source]¶

Bases: kitty.model.low_level.encoder.StrEncoder

Encode the string as c-string, with null at the end

encode(value)[source]¶

Parameters:	value – value to encode