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Line 119: − + − − {{Code|avoiding garbage collection|<syntaxhighlight lang="octave" style="font-size:13px" line highlight="4"> − pyexec('d = dict(one=1, two=2)') # create object in Python − x = pyobj('d') # create pyobj wrapper for that object − pyexec('d = []') # careful, don't lose the object to the GC − x.keys() # list the keys of the dict − clear x # now the object could be GCed − </syntaxhighlight>}} − − One proposed way to do this: − − 1. `x` stores the pointer to `d`. The `@pyobj` ctor creates a dummy reference to `d`, this prevents GC − − 2. on deletion of x (`clear x`) we delete the dummy reference in Python. − − Notes: − − * Seems like the relevant "pointer" is {{Codeline|id()}}. Haven't seen yet how to access an object from its id, except that its a bad idea... − − * My plan to create a dict in Python, indexed by {{Codeline|hex(id(x))}}, maybe called {{Codeline|__InOct__}}. Then pass the id of the object to the {{Codeline|@pyobj/pyobj}} constructor. − − * Follow along and help out here: https://bitbucket.org/macdonald/pytave/commits/branch/cbm_pyobj − − * Rejected idea: store the `repr` as a string in `x`. But this makes a copy of the object rather than a reference to the original object. − − ====== Interface design ====== − − * {{Codeline|pyeval}} should be modified to return a {{Codeline|@pyobj}} for things that it cannot convert to Octave-native types. See the `networkx` example above: `G` could be returned by `pyeval`. − − * {{Codeline|@pyobj/pyobj}} constructor would not normally be called by users.
→Python Objects in Octave: clean-up pyobj section: this is basically working, rather than design
==== Python Objects in Octave ====
==== Python Objects in Octave ====
The {{Codeline|@pyobj}} classdef class is intended to wrap arbitrary Python objects so they can be accessed an manipulated from within Octave.
The {{Codeline|@pyobject}} class wraps arbitrary Python objects so they can be accessed and manipulated from within Octave. In most cases, these are created automatically.
== Known Problems ==
== Known Problems ==