The backend used for doctests

This backend is active during doctests. It should mimic the behavior of the IPython command line as close as possible. Without actually launching image viewers, of course.

EXAMPLES:

sage: from sage.repl.rich_output import get_display_manager
sage: get_display_manager()
The Sage display manager using the doctest backend

class sage.repl.rich_output.backend_doctest.BackendDoctest

Bases: BackendBase

default_preferences()

Return the backend’s display preferences

Matches the IPython command line display preferences to keep the differences between that and the doctests to a minimum.

OUTPUT:

Instance of DisplayPreferences.

EXAMPLES:

sage: from sage.repl.rich_output.backend_ipython import BackendIPythonCommandline
sage: backend = BackendIPythonCommandline()
sage: backend.default_preferences()
Display preferences:
* align_latex is not specified
* graphics is not specified
* supplemental_plot = never
* text is not specified

display_immediately(plain_text, rich_output)

Display object immediately

INPUT:

Same as displayhook().

EXAMPLES:

The following example does not call the displayhook. More precisely, the show() method returns None which is ignored by the displayhook. When running the example on a Sage display backend capable of displaying graphics outside of the displayhook, the plot is still shown. Nothing is shown during doctests:

sage: plt = plot(sin)                                                       # needs sage.plot sage.symbolic
sage: plt                                                                   # needs sage.plot sage.symbolic
Graphics object consisting of 1 graphics primitive
sage: plt.show()                                                            # needs sage.plot sage.symbolic

sage: from sage.repl.rich_output import get_display_manager
sage: dm = get_display_manager()
sage: dm.display_immediately(plt)   # indirect doctest                      # needs sage.plot sage.symbolic

displayhook(plain_text, rich_output)

Display object from displayhook

INPUT:

• plain_text – instance of OutputPlainText. The plain text version of the output.

• rich_output – instance of an output container class (subclass of OutputBase). Guaranteed to be one of the output containers returned from supported_output(), possibly the same as plain_text.

EXAMPLES:

This ends up calling the displayhook:

sage: plt = plot(sin)                                                       # needs sage.plot sage.symbolic
sage: plt                                                                   # needs sage.plot sage.symbolic
Graphics object consisting of 1 graphics primitive
sage: plt.show()                                                            # needs sage.plot sage.symbolic

sage: from sage.repl.rich_output import get_display_manager
sage: dm = get_display_manager()
sage: dm.displayhook(plt)       # indirect doctest                          # needs sage.plot sage.symbolic
Graphics object consisting of 1 graphics primitive

install(**kwds)

Switch to the doctest backend.

This method is being called from within switch_backend(). You should never call it by hand.

INPUT:

None of the optional keyword arguments are used in the doctest backend.

EXAMPLES:

sage: from sage.repl.rich_output.backend_doctest import BackendDoctest
sage: backend = BackendDoctest()
sage: backend.install()
sage: backend.uninstall()

supported_output()

Return the supported output types

OUTPUT:

Set of subclasses of OutputBase, the supported output container types.

EXAMPLES:

sage: from sage.repl.rich_output.backend_doctest import BackendDoctest
sage: from sage.repl.rich_output.output_catalog import *
sage: backend = BackendDoctest()
sage: OutputPlainText in backend.supported_output()
True
sage: OutputSceneJmol in backend.supported_output()
True

uninstall()

Switch away from the doctest backend

This method is being called from within switch_backend(). You should never call it by hand.

EXAMPLES:

sage: from sage.repl.rich_output.backend_doctest import BackendDoctest
sage: backend = BackendDoctest()
sage: backend.install()
sage: backend.uninstall()

validate(rich_output)

Perform checks on rich_output

INPUT:

• rich_output – instance of a subclass of OutputBase.

OUTPUT:

An assertion is triggered if rich_output is invalid.

EXAMPLES:

sage: from sage.repl.rich_output import get_display_manager
sage: dm = get_display_manager()
sage: invalid = dm.types.OutputImagePng('invalid')
sage: backend = dm._backend;  backend
doctest
sage: backend.validate(invalid)
Traceback (most recent call last):
...
AssertionError
sage: backend.validate(dm.types.OutputPlainText.example())
sage: backend.validate(dm.types.OutputAsciiArt.example())
sage: backend.validate(dm.types.OutputLatex.example())
sage: backend.validate(dm.types.OutputImagePng.example())
sage: backend.validate(dm.types.OutputImageGif.example())
sage: backend.validate(dm.types.OutputImageJpg.example())
sage: backend.validate(dm.types.OutputImageSvg.example())
sage: backend.validate(dm.types.OutputImagePdf.example())
sage: backend.validate(dm.types.OutputImageDvi.example())
sage: backend.validate(dm.types.OutputSceneJmol.example())
sage: backend.validate(dm.types.OutputSceneWavefront.example())
sage: backend.validate(dm.types.OutputSceneCanvas3d.example())
sage: backend.validate(dm.types.OutputVideoOgg.example())
sage: backend.validate(dm.types.OutputVideoWebM.example())
sage: backend.validate(dm.types.OutputVideoMp4.example())
sage: backend.validate(dm.types.OutputVideoFlash.example())
sage: backend.validate(dm.types.OutputVideoMatroska.example())
sage: backend.validate(dm.types.OutputVideoAvi.example())
sage: backend.validate(dm.types.OutputVideoWmv.example())
sage: backend.validate(dm.types.OutputVideoQuicktime.example())