AMQP Types¶

These tables summarize the various AMQP types and their Python API equivalents as used in the API.

Scalar Types¶

AMQP Type	Proton C API Type	Proton Python API Type	Description
null	PN_NONE	`None`	Indicates an empty value.
boolean	PN_BOOL	`bool`	Represents a true or false value.
ubyte	PN_UBYTE	`proton.ubyte`	Integer in the range \(0\) to \(2^8 - 1\) inclusive.
byte	PN_BYTE	`proton.byte`	Integer in the range \(-(2^7)\) to \(2^7 - 1\) inclusive.
ushort	PN_USHORT	`proton.ushort`	Integer in the range \(0\) to \(2^{16} - 1\) inclusive.
short	PN_SHORT	`proton.short`	Integer in the range \(-(2^{15})\) to \(2^{15} - 1\) inclusive.
uint	PN_UINT	`proton.uint`	Integer in the range \(0\) to \(2^{32} - 1\) inclusive.
int	PN_INT	`proton.int32`	Integer in the range \(-(2^{31})\) to \(2^{31} - 1\) inclusive.
char	PN_CHAR	`proton.char`	A single Unicode character.
ulong	PN_ULONG	`proton.ulong`	Integer in the range \(0\) to \(2^{64} - 1\) inclusive.
long	PN_LONG	`int` or `long`	Integer in the range \(-(2^{63})\) to \(2^{63} - 1\) inclusive.
timestamp	PN_TIMESTAMP	`proton.timestamp`	An absolute point in time with millisecond precision.
float	PN_FLOAT	`proton.float32`	32-bit floating point number (IEEE 754-2008 binary32).
double	PN_DOUBLE	`double`	64-bit floating point number (IEEE 754-2008 binary64).
decimal32	PN_DECIMAL32	`proton.decimal32`	32-bit decimal number (IEEE 754-2008 decimal32).
decimal64	PN_DECIMAL64	`proton.decimal64`	64-bit decimal number (IEEE 754-2008 decimal64).
decimal128	PN_DECIMAL128	`proton.decimal128`	128-bit decimal number (IEEE 754-2008 decimal128).
uuid	PN_UUID	`uuid.UUID`	A universally unique identifier as defined by RFC-4122 section 4.1.2.
binary	PN_BINARY	`bytes`	A sequence of octets.
string	PN_STRING	`str`	A sequence of Unicode characters.
symbol	PN_SYMBOL	`proton.symbol`	Symbolic values from a constrained domain.

Compound Types¶

AMQP Type	Proton C API Type	Proton Python API Type	Description
array	PN_ARRAY	`proton.Array`	A sequence of values of a single type.
list	PN_LIST	`list`	A sequence of polymorphic values.
map	PN_MAP	`dict`	A polymorphic mapping from distinct keys to values.

Specialized Types¶

The following classes implement specialized or restricted types to help enforce type restrictions in the AMQP specification.

Proton Python API Type	Description	Where used in API
`proton.SymbolList`	A `list` that only accepts `proton.symbol` elements. However, will silently convert strings to symbols.	`proton.Connection.desired_capabilities` `proton.Connection.offered_capabilities`
`proton.PropertyDict`	A `dict` that only accppts `proton.symbol` keys. However, will silently convert strings to symbols.	`proton.Connection.properties`
`proton.AnnotationDict`	A `dict` that only accppts `proton.symbol` or `proton.ulong` keys. However, will silently convert strings to symbols.	`proton.Message.annotations` `proton.Message.instructions`

These types would typically be used where the the above attributes are set. They will silently convert strings to symbols, but will raise an error if a not-allowed type is used. For example:

>>> from proton import symbol, ulong, Message, AnnotationDict
>>> msg = Message()
>>> msg.annotations = AnnotationDict({'one':1, symbol('two'):2, ulong(3):'three'})
>>> msg.annotations
AnnotationDict({symbol('one'): 1, symbol('two'): 2, ulong(3): 'three'})
>>> m.instructions = AnnotationDict({'one':1, symbol('two'):2, ulong(3):'three', 4:'four'})
  ...
KeyError: "invalid non-symbol key: <class 'int'>: 4"
>>> m.instructions
>>>