This documentation covers IPython versions 6.0 and higher. Beginning with version 6.0, IPython stopped supporting compatibility with Python versions lower than 3.3 including all versions of Python 2.7.
If you are looking for an IPython version compatible with Python 2.7, please use the IPython 5.x LTS release and refer to its documentation (LTS is the long term support release).
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
falls back to a standard
class Shout(object): def __init__(self, text): self.text = text def _repr_html_(self): return "<h1>" + self.text + "</h1>"
There are also two more powerful display methods:
Should return a dictionary of multiple formats, keyed by mimetype, or a tuple of two dictionaries: data, metadata. If this returns something, other
_repr_*_methods are ignored. The method should take keyword arguments
exclude, though it is not required to respect them.
Displays the object as a side effect; the return value is ignored. If this is defined, all other display methods are ignored.
Formatters for third-party types¶
The user can also register formatters for types without modifying the class:
from bar import Foo def foo_html(obj): return '<marquee>Foo object %s</marquee>' % obj.name html_formatter = get_ipython().display_formatter.formatters['text/html'] html_formatter.for_type(Foo, foo_html) # Or register a type without importing it - this does the same as above: html_formatter.for_type_by_name('bar.Foo', foo_html)
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.