2.13 aepack -- Conversion between Python variables and AppleEvent data containers

2.13 aepack -- Conversion between Python variables and AppleEvent data containers

Availability: Macintosh.

The aepack module defines functions for converting (packing) Python variables to AppleEvent descriptors and back (unpacking). Within Python the AppleEvent descriptor is handled by Python objects of built-in type AEDesc, defined in module AE.

The aepack module defines the following functions:

pack(x[, forcetype])

Returns an AEDesc object containing a conversion of Python value x. If forcetype is provided it specifies the descriptor type of the result. Otherwise, a default mapping of Python types to Apple Event descriptor types is used, as follows:

Python type descriptor type

FSSpec typeFSS
Alias typeAlias
integer typeLong (32 bit integer)
float typeFloat (64 bit floating point)
string typeText
list typeAEList
dictionary typeAERecord
instance see below

FSSpec and Alias are built-in object types defined in the module macfs.

If x is a Python instance then this function attempts to call an __aepack__() method. This method should return an AE.AEDesc object.

If the conversion x is not defined above, this function returns the Python string representation of a value (the repr() function) encoded as a text descriptor.

unpack(x)

x must be an object of type AEDesc. This function returns a Python object representation of the data in the Apple Event descriptor x. Simple AppleEvent data types (integer, text, float) are returned as their obvious Python counterparts. Apple Event lists are returned as Python lists, and the list elements are recursively unpacked. Object references (ex. line 3 of document 1) are returned as instances of aetypes.ObjectSpecifier. AppleEvent descriptors with descriptor type typeFSS are returned as FSSpec objects. AppleEvent record descriptors are returned as Python dictionaries, with keys of type ? and elements recursively unpacked.

See Also:

Module AE:: Built-in access to Apple Event Manager routines.

Module aetypes:: Python definitions of codes for Apple Event descriptor types.

Inside Macintosh: Interapplication Communication: Information about inter-process communications on the Macintosh.

See About this document... for information on suggesting changes.