Integrating your objects with IPython¶
To change the attributes displayed by tab-completing your object, define a
__dir__(self) method for it. For more details, see the documentation of the
built-in dir() function.
You can also customise key completions for your objects, e.g. pressing tab after
obj["a. To do so, define a method
returns a list of objects which are possible keys in a subscript expression
New in version 5.0: Custom key completions
The notebook and the Qt console can display richer representations of objects.
To use this, you can define any of a number of
_repr_*_() methods. Note that
these are surrounded by single, not double underscores.
Both the notebook and the Qt console can display
representations. The notebook can also display
latex. If the methods don’t exist, or return
None, it falls
back to a standard
class Shout(object): def __init__(self, text): self.text = text def _repr_html_(self): return "<h1>" + self.text + "</h1>"
Custom exception tracebacks¶
Rarely, you might want to display a custom traceback when reporting an
exception. To do this, define the custom traceback using
_render_traceback_(self) method which returns a list of strings, one string
for each line of the traceback. For example, the ipyparallel a parallel computing framework for
IPython, does this to display errors from multiple engines.
Please be conservative in using this feature; by replacing the default traceback you may hide important information from the user.