twisted.protocols.amp.Argument

Base-class of all objects that take values from Amp packets and convert them into objects for Python functions.

This implementation of IArgumentType provides several higher-level hooks for subclasses to override. See toString and fromString which will be used to define the behavior of IArgumentType.toBox and IArgumentType.fromBox, respectively.

def __init__(self, optional=False):

Create an Argument.

Parameters optional a boolean indicating whether this argument can be omitted in the protocol.

def retrieve(self, d, name, proto):

Retrieve the given key from the given dictionary, removing it if found.

Parameters	d	a dictionary.
	name	a key in d.
	proto	an instance of an AMP.
Returns	d[name].
Raises	KeyError	if I am not optional and no value was found.

def fromBox(self, name, strings, objects, proto):

Populate an 'out' dictionary with mapping names to Python values decoded from an 'in' AmpBox mapping strings to string values.

Parameters	name	the argument name to retrieve (type: `bytes`)
	strings	The AmpBox to read string(s) from, a mapping of argument names to string values. (type: AmpBox)
	objects	The dictionary to write object(s) to, a mapping of names to Python objects. Keys will be native strings. (type: dict)
	proto	an AMP instance.

def toBox(self, name, strings, objects, proto):

Populate an 'out' AmpBox with strings encoded from an 'in' dictionary mapping names to Python values.

Parameters	name	the argument name to retrieve (type: `bytes`)
	strings	The AmpBox to write string(s) to, a mapping of argument names to string values. (type: AmpBox)
	objects	The dictionary to read object(s) from, a mapping of names to Python objects. Keys should be native strings. (type: dict)
	proto	the protocol we are converting for. (type: AMP)

def fromStringProto(self, inString, proto):

Convert a string to a Python value.

Parameters	inString	the string to convert. (type: `bytes`)
	proto	the protocol we are converting for. (type: AMP)
Returns	a Python object.

def toStringProto(self, inObject, proto):

Convert a Python object to a string.

Parameters	inObject	the object to convert.
	proto	the protocol we are converting for. (type: AMP)

def fromString(self, inString):

Convert a string to a Python object. Subclasses must implement this.

Parameters	inString	the string to convert. (type: `bytes`)
Returns	the decoded value from `inString`

def toString(self, inObject):

Convert a Python object into a string for passing over the network.

Parameters	inObject	an object of the type that this Argument is intended to deal with.
Returns	the wire encoding of inObject (type: `bytes`)

Method	__init__	Create an Argument.
Method	retrieve	Retrieve the given key from the given dictionary, removing it if found.
Method	fromBox	Populate an 'out' dictionary with mapping names to Python values decoded from an 'in' AmpBox mapping strings to string values.
Method	toBox	Populate an 'out' AmpBox with strings encoded from an 'in' dictionary mapping names to Python values.
Method	fromStringProto	Convert a string to a Python value.
Method	toStringProto	Convert a Python object to a string.
Method	fromString	Convert a string to a Python object. Subclasses must implement this.
Method	toString	Convert a Python object into a string for passing over the network.

twisted.protocols.amp.Argument class documentation