IPython Displayhook Formatters¶
The classes in this module can be used as IPython displayhook formatters. It has two main features, by default the displayhook contains a new facility for displaying lists of matrices in an easier to read format:
sage: [identity_matrix(i) for i in range(2,5)]
[
[1 0 0 0]
[1 0 0] [0 1 0 0]
[1 0] [0 1 0] [0 0 1 0]
[0 1], [0 0 1], [0 0 0 1]
]
This facility uses _repr_()
(and a simple string) to try do a nice read
format (see sage.structure.parent.Parent._repr_option()
for details).
With this displayhook there exists an other way for displaying object and more generally, all sage expression as an ASCII art object:
sage: from sage.repl.interpreter import get_test_shell
sage: shell = get_test_shell()
sage: shell.run_cell('%display ascii_art')
sage: shell.run_cell('integral(x^2/pi^x, x)')
/ 2 2 \ -x*log(pi)
-\x *log (pi) + 2*x*log(pi) + 2/*e
---------------------------------------------
3
log (pi)
sage: shell.run_cell("i = var('i')")
sage: shell.run_cell('sum(i*x^i, i, 0, 10)')
10 9 8 7 6 5 4 3 2
10*x + 9*x + 8*x + 7*x + 6*x + 5*x + 4*x + 3*x + 2*x + x
sage: shell.run_cell('StandardTableaux(4).list()')
[
[ 1 4
[ 1 3 4 1 2 4 1 2 3 1 3 1 2 2
[ 1 2 3 4, 2 , 3 , 4 , 2 4, 3 4, 3 ,
<BLANKLINE>
1 ]
1 3 1 2 2 ]
2 3 3 ]
4 , 4 , 4 ]
sage: shell.run_cell('%display default')
sage: shell.quit()
This other facility uses a simple
AsciiArt
object (see and
sage.structure.sage_object.SageObject._ascii_art_()
).
-
class
sage.repl.display.formatter.
SageDisplayFormatter
(*args, **kwds)¶ Bases:
IPython.core.formatters.DisplayFormatter
This is where the Sage rich objects are translated to IPython
INPUT/OUTPUT:
See the IPython documentation.
EXAMPLES:
This is part of how Sage works with the IPython output system. It cannot be used in doctests:
sage: from sage.repl.display.formatter import SageDisplayFormatter sage: fmt = SageDisplayFormatter() Traceback (most recent call last): ... RuntimeError: check failed: current backend is invalid
-
format
(obj, include=None, exclude=None)¶ Use the Sage rich output instead of IPython
INPUT/OUTPUT:
See the IPython documentation.
EXAMPLES:
sage: [identity_matrix(i) for i in range(3,7)] [ [1 0 0 0 0 0] [1 0 0 0 0] [0 1 0 0 0 0] [1 0 0 0] [0 1 0 0 0] [0 0 1 0 0 0] [1 0 0] [0 1 0 0] [0 0 1 0 0] [0 0 0 1 0 0] [0 1 0] [0 0 1 0] [0 0 0 1 0] [0 0 0 0 1 0] [0 0 1], [0 0 0 1], [0 0 0 0 1], [0 0 0 0 0 1] ] sage: from sage.repl.interpreter import get_test_shell sage: shell = get_test_shell() sage: shell.run_cell('%display ascii_art') # indirect doctest sage: shell.run_cell("i = var('i')") sage: shell.run_cell('sum(i*x^i, i, 0, 10)') 10 9 8 7 6 5 4 3 2 10*x + 9*x + 8*x + 7*x + 6*x + 5*x + 4*x + 3*x + 2*x + x sage: shell.run_cell('%display default') sage: shell.quit()
TESTS:
sage: import os sage: from sage.env import SAGE_EXTCODE sage: example_png = os.path.join(SAGE_EXTCODE, 'doctest', 'rich_output', 'example.png') sage: from sage.repl.rich_output.backend_ipython import BackendIPython sage: backend = BackendIPython() sage: shell = get_test_shell() sage: backend.install(shell=shell) sage: shell.run_cell('get_ipython().display_formatter') <sage.repl.display.formatter.SageDisplayFormatter object at 0x...> sage: shell.run_cell('from IPython.display import Image') sage: shell.run_cell('ipython_image = Image("{0}")'.format(example_png)) sage: shell.run_cell('ipython_image') <IPython.core.display.Image object> sage: shell.run_cell('get_ipython().display_formatter.format(ipython_image)') ({u'image/png': '\x89PNG...', u'text/plain': u'<IPython.core.display.Image object>'}, {})
Test that
__repr__
is only called once when generating text output:sage: class Repper(object): ....: def __repr__(self): ....: print('__repr__ called') ....: return 'I am repper' sage: Repper() __repr__ called I am repper
-
-
class
sage.repl.display.formatter.
SagePlainTextFormatter
(*args, **kwds)¶ Bases:
IPython.core.formatters.PlainTextFormatter
Improved plain text IPython formatter.
In particular, it correctly print lists of matrices or other objects (see
sage.structure.parent.Parent._repr_option()
).Warning
This IPython formatter is NOT used. You could use it to enable Sage formatting in IPython, but Sage uses its own rich output system that is more flexible and supports different backends.
INPUT/OUTPUT:
See the IPython documentation.
EXAMPLES:
sage: from sage.repl.interpreter import get_test_shell sage: shell = get_test_shell() sage: shell.display_formatter.formatters['text/plain'] <IPython.core.formatters.PlainTextFormatter object at 0x...> sage: shell.quit()