Editing Pythonic
Jump to navigation
Jump to search
The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then publish the changes below to finish undoing the edit.
Latest revision | Your text | ||
Line 125: | Line 125: | ||
This section documents some known problems or limitations of the Python calling interface, usually due to a limitation of the Octave language itself or a bug in Octave that needs some attention. | This section documents some known problems or limitations of the Python calling interface, usually due to a limitation of the Octave language itself or a bug in Octave that needs some attention. | ||
<ul> | <ul> | ||
<li>Assignment to <tt>dict</tt> or other mapping object with string keys fails. The following syntax produces an error: | |||
<li>Assignment to <tt>dict</tt> or other mapping object | |||
{{Code||<syntaxhighlight lang="octave"> | {{Code||<syntaxhighlight lang="octave"> | ||
d = py.dict (); | d = py.dict (); | ||
Line 142: | Line 137: | ||
</syntaxhighlight>}} | </syntaxhighlight>}} | ||
The reason is because Octave strings are interpreted as arrays in many contexts, and this syntax is parsed by Octave as an attempt to assign to 3 elements of an object.</li> | The reason is because Octave strings are interpreted as arrays in many contexts, and this syntax is parsed by Octave as an attempt to assign to 3 elements of an object.</li> | ||
<li>Element indexing on a <tt>list</tt> or other sequence object with a range or set of indices doesn't return the right number of output arguments. Element indexing should return as many values as were indexed, each assigned to the <tt>ans</tt> variable in turn, or be able to wrap the return list in a cell array, as shown here: | <li>Element indexing on a <tt>list</tt> or other sequence object with a range or set of indices doesn't return the right number of output arguments. Element indexing should return as many values as were indexed, each assigned to the <tt>ans</tt> variable in turn, or be able to wrap the return list in a cell array, as shown here: | ||
{{Code||<syntaxhighlight lang="octave"> | {{Code||<syntaxhighlight lang="octave"> | ||
Line 154: | Line 148: | ||
[y{1:3}] = x{1:3}; | [y{1:3}] = x{1:3}; | ||
</syntaxhighlight>}}</li> | </syntaxhighlight>}}</li> | ||
<li>Function handles to Python functions, bound methods, or other callable objects is not yet supported. As a workaround, the {{Codeline|pyeval}} function can be used to return a reference to a function which can be assigned and called like any Octave function handle, but cannot be passed in to functions that expect a function handle.</li> | <li>Function handles to Python functions, bound methods, or other callable objects is not yet supported. As a workaround, the {{Codeline|pyeval}} function can be used to return a reference to a function which can be assigned and called like any Octave function handle, but cannot be passed in to functions that expect a function handle.</li> | ||
<li>Objects are not deleted because object destructors are not called by Octave when objects are cleared or go out of scope. For the Python interface, this means that the internal store of objects will continue to grow and objects will persist indefinitely even when all Octave references to a given Python object are gone. This is Octave bug {{Bug|46497}}.</li> | <li>Objects are not deleted because object destructors are not called by Octave when objects are cleared or go out of scope. For the Python interface, this means that the internal store of objects will continue to grow and objects will persist indefinitely even when all Octave references to a given Python object are gone. This is Octave bug {{Bug|46497}}.</li> | ||
</ul> | </ul> | ||