Class inheritance graphs

sage.misc.classgraph.class_graph(top, depth=5, name_filter=None, classes=None, as_graph=True)

Returns the class inheritance graph of a module, class, or object


  • top – the module, class, or object to start with (e.g. sage, Integer, 3)
  • depth – maximal recursion depth within submodules (default: 5)
  • name_filter – e.g. ‘sage.rings’ to only consider classes in sage.rings
  • classes – optional dictionary to be filled in (it is also returned)
  • as_graph – a boolean (default: True)


  • An oriented graph, with class names as vertices, and an edge from each class to each of its bases.


We construct the inheritance graph of the classes within a given module:

sage: from sage.rings.polynomial.padics import polynomial_padic_capped_relative_dense, polynomial_padic_flat
sage: G = class_graph(sage.rings.polynomial.padics); G
Digraph on 6 vertices
sage: G.vertices()
sage: G.edges(labels=False)
[('Polynomial_padic', 'Polynomial'),
 ('Polynomial_padic_capped_relative_dense', 'Polynomial_generic_cdv'),
 ('Polynomial_padic_capped_relative_dense', 'Polynomial_padic'),
 ('Polynomial_padic_flat', 'Polynomial_generic_dense'),
 ('Polynomial_padic_flat', 'Polynomial_padic')]

We construct the inheritance graph of a given class:

sage: class_graph(Parent).edges(labels=False)
[('CategoryObject', 'SageObject'), ('Parent', 'CategoryObject'), ('SageObject', 'object')]

We construct the inheritance graph of the class of an object:

sage: class_graph([1,2,3]).edges(labels=False)
[('list', 'object')]


the output of class_graph used to be a dictionary mapping each class name to the list of names of its bases. This can be emulated by setting the option as_graph to False:

sage: class_graph(sage.rings.polynomial.padics, depth=2, as_graph=False)
{'Polynomial_padic': ['Polynomial'],
 'Polynomial_padic_capped_relative_dense': ['Polynomial_generic_cdv',
 'Polynomial_padic_flat': ['Polynomial_generic_dense', 'Polynomial_padic']}


the classes and as_graph options are mostly intended for internal recursive use.


class_graph does not yet handle nested classes