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"""Tools for setting up printing in interactive sessions. """
from io import BytesIO
from sympy.printing.latex import latex as default_latex
from sympy.printing.preview import preview
from sympy.utilities.misc import debug
from sympy.printing.defaults import Printable
from sympy.external import import_module
def _init_python_printing(stringify_func, **settings):
"""Setup printing in Python interactive session. """
import sys
import builtins
def _displayhook(arg):
"""Python's pretty-printer display hook.
This function was adapted from:
https://www.python.org/dev/peps/pep-0217/
"""
if arg is not None:
builtins._ = None
print(stringify_func(arg, **settings))
builtins._ = arg
sys.displayhook = _displayhook
def _init_ipython_printing(ip, stringify_func, use_latex, euler, forecolor,
backcolor, fontsize, latex_mode, print_builtin,
latex_printer, scale, **settings):
"""Setup printing in IPython interactive session. """
IPython = import_module("IPython", min_module_version="1.0")
try:
from IPython.lib.latextools import latex_to_png
except ImportError:
pass
# Guess best font color if none was given based on the ip.colors string.
# From the IPython documentation:
# It has four case-insensitive values: 'nocolor', 'neutral', 'linux',
# 'lightbg'. The default is neutral, which should be legible on either
# dark or light terminal backgrounds. linux is optimised for dark
# backgrounds and lightbg for light ones.
if forecolor is None:
color = ip.colors.lower()
if color == 'lightbg':
forecolor = 'Black'
elif color == 'linux':
forecolor = 'White'
else:
# No idea, go with gray.
forecolor = 'Gray'
debug("init_printing: Automatic foreground color:", forecolor)
if use_latex == "svg":
extra_preamble = "\n\\special{color %s}" % forecolor
else:
extra_preamble = ""
imagesize = 'tight'
offset = "0cm,0cm"
resolution = round(150*scale)
dvi = r"-T %s -D %d -bg %s -fg %s -O %s" % (
imagesize, resolution, backcolor, forecolor, offset)
dvioptions = dvi.split()
svg_scale = 150/72*scale
dvioptions_svg = ["--no-fonts", "--scale={}".format(svg_scale)]
debug("init_printing: DVIOPTIONS:", dvioptions)
debug("init_printing: DVIOPTIONS_SVG:", dvioptions_svg)
latex = latex_printer or default_latex
def _print_plain(arg, p, cycle):
"""caller for pretty, for use in IPython 0.11"""
if _can_print(arg):
p.text(stringify_func(arg))
else:
p.text(IPython.lib.pretty.pretty(arg))
def _preview_wrapper(o):
exprbuffer = BytesIO()
try:
preview(o, output='png', viewer='BytesIO', euler=euler,
outputbuffer=exprbuffer, extra_preamble=extra_preamble,
dvioptions=dvioptions, fontsize=fontsize)
except Exception as e:
# IPython swallows exceptions
debug("png printing:", "_preview_wrapper exception raised:",
repr(e))
raise
return exprbuffer.getvalue()
def _svg_wrapper(o):
exprbuffer = BytesIO()
try:
preview(o, output='svg', viewer='BytesIO', euler=euler,
outputbuffer=exprbuffer, extra_preamble=extra_preamble,
dvioptions=dvioptions_svg, fontsize=fontsize)
except Exception as e:
# IPython swallows exceptions
debug("svg printing:", "_preview_wrapper exception raised:",
repr(e))
raise
return exprbuffer.getvalue().decode('utf-8')
def _matplotlib_wrapper(o):
# mathtext can't render some LaTeX commands. For example, it can't
# render any LaTeX environments such as array or matrix. So here we
# ensure that if mathtext fails to render, we return None.
try:
try:
return latex_to_png(o, color=forecolor, scale=scale)
except TypeError: # Old IPython version without color and scale
return latex_to_png(o)
except ValueError as e:
debug('matplotlib exception caught:', repr(e))
return None
# Hook methods for builtin SymPy printers
printing_hooks = ('_latex', '_sympystr', '_pretty', '_sympyrepr')
def _can_print(o):
"""Return True if type o can be printed with one of the SymPy printers.
If o is a container type, this is True if and only if every element of
o can be printed in this way.
"""
try:
# If you're adding another type, make sure you add it to printable_types
# later in this file as well
builtin_types = (list, tuple, set, frozenset)
if isinstance(o, builtin_types):
# If the object is a custom subclass with a custom str or
# repr, use that instead.
if (type(o).__str__ not in (i.__str__ for i in builtin_types) or
type(o).__repr__ not in (i.__repr__ for i in builtin_types)):
return False
return all(_can_print(i) for i in o)
elif isinstance(o, dict):
return all(_can_print(i) and _can_print(o[i]) for i in o)
elif isinstance(o, bool):
return False
elif isinstance(o, Printable):
# types known to SymPy
return True
elif any(hasattr(o, hook) for hook in printing_hooks):
# types which add support themselves
return True
elif isinstance(o, (float, int)) and print_builtin:
return True
return False
except RuntimeError:
return False
# This is in case maximum recursion depth is reached.
# Since RecursionError is for versions of Python 3.5+
# so this is to guard against RecursionError for older versions.
def _print_latex_png(o):
"""
A function that returns a png rendered by an external latex
distribution, falling back to matplotlib rendering
"""
if _can_print(o):
s = latex(o, mode=latex_mode, **settings)
if latex_mode == 'plain':
s = '$\\displaystyle %s$' % s
try:
return _preview_wrapper(s)
except RuntimeError as e:
debug('preview failed with:', repr(e),
' Falling back to matplotlib backend')
if latex_mode != 'inline':
s = latex(o, mode='inline', **settings)
return _matplotlib_wrapper(s)
def _print_latex_svg(o):
"""
A function that returns a svg rendered by an external latex
distribution, no fallback available.
"""
if _can_print(o):
s = latex(o, mode=latex_mode, **settings)
if latex_mode == 'plain':
s = '$\\displaystyle %s$' % s
try:
return _svg_wrapper(s)
except RuntimeError as e:
debug('preview failed with:', repr(e),
' No fallback available.')
def _print_latex_matplotlib(o):
"""
A function that returns a png rendered by mathtext
"""
if _can_print(o):
s = latex(o, mode='inline', **settings)
return _matplotlib_wrapper(s)
def _print_latex_text(o):
"""
A function to generate the latex representation of SymPy expressions.
"""
if _can_print(o):
s = latex(o, mode=latex_mode, **settings)
if latex_mode == 'plain':
return '$\\displaystyle %s$' % s
return s
# Printable is our own type, so we handle it with methods instead of
# the approach required by builtin types. This allows downstream
# packages to override the methods in their own subclasses of Printable,
# which avoids the effects of gh-16002.
printable_types = [float, tuple, list, set, frozenset, dict, int]
plaintext_formatter = ip.display_formatter.formatters['text/plain']
# Exception to the rule above: IPython has better dispatching rules
# for plaintext printing (xref ipython/ipython#8938), and we can't
# use `_repr_pretty_` without hitting a recursion error in _print_plain.
for cls in printable_types + [Printable]:
plaintext_formatter.for_type(cls, _print_plain)
svg_formatter = ip.display_formatter.formatters['image/svg+xml']
if use_latex in ('svg', ):
debug("init_printing: using svg formatter")
for cls in printable_types:
svg_formatter.for_type(cls, _print_latex_svg)
Printable._repr_svg_ = _print_latex_svg
else:
debug("init_printing: not using any svg formatter")
for cls in printable_types:
# Better way to set this, but currently does not work in IPython
#png_formatter.for_type(cls, None)
if cls in svg_formatter.type_printers:
svg_formatter.type_printers.pop(cls)
Printable._repr_svg_ = Printable._repr_disabled
png_formatter = ip.display_formatter.formatters['image/png']
if use_latex in (True, 'png'):
debug("init_printing: using png formatter")
for cls in printable_types:
png_formatter.for_type(cls, _print_latex_png)
Printable._repr_png_ = _print_latex_png
elif use_latex == 'matplotlib':
debug("init_printing: using matplotlib formatter")
for cls in printable_types:
png_formatter.for_type(cls, _print_latex_matplotlib)
Printable._repr_png_ = _print_latex_matplotlib
else:
debug("init_printing: not using any png formatter")
for cls in printable_types:
# Better way to set this, but currently does not work in IPython
#png_formatter.for_type(cls, None)
if cls in png_formatter.type_printers:
png_formatter.type_printers.pop(cls)
Printable._repr_png_ = Printable._repr_disabled
latex_formatter = ip.display_formatter.formatters['text/latex']
if use_latex in (True, 'mathjax'):
debug("init_printing: using mathjax formatter")
for cls in printable_types:
latex_formatter.for_type(cls, _print_latex_text)
Printable._repr_latex_ = _print_latex_text
else:
debug("init_printing: not using text/latex formatter")
for cls in printable_types:
# Better way to set this, but currently does not work in IPython
#latex_formatter.for_type(cls, None)
if cls in latex_formatter.type_printers:
latex_formatter.type_printers.pop(cls)
Printable._repr_latex_ = Printable._repr_disabled
def _is_ipython(shell):
"""Is a shell instance an IPython shell?"""
# shortcut, so we don't import IPython if we don't have to
from sys import modules
if 'IPython' not in modules:
return False
try:
from IPython.core.interactiveshell import InteractiveShell
except ImportError:
# IPython < 0.11
try:
from IPython.iplib import InteractiveShell
except ImportError:
# Reaching this points means IPython has changed in a backward-incompatible way
# that we don't know about. Warn?
return False
return isinstance(shell, InteractiveShell)
# Used by the doctester to override the default for no_global
NO_GLOBAL = False
def init_printing(pretty_print=True, order=None, use_unicode=None,
use_latex=None, wrap_line=None, num_columns=None,
no_global=False, ip=None, euler=False, forecolor=None,
backcolor='Transparent', fontsize='10pt',
latex_mode='plain', print_builtin=True,
str_printer=None, pretty_printer=None,
latex_printer=None, scale=1.0, **settings):
r"""
Initializes pretty-printer depending on the environment.
Parameters
==========
pretty_print : bool, default=True
If ``True``, use :func:`~.pretty_print` to stringify or the provided pretty
printer; if ``False``, use :func:`~.sstrrepr` to stringify or the provided string
printer.
order : string or None, default='lex'
There are a few different settings for this parameter:
``'lex'`` (default), which is lexographic order;
``'grlex'``, which is graded lexographic order;
``'grevlex'``, which is reversed graded lexographic order;
``'old'``, which is used for compatibility reasons and for long expressions;
``None``, which sets it to lex.
use_unicode : bool or None, default=None
If ``True``, use unicode characters;
if ``False``, do not use unicode characters;
if ``None``, make a guess based on the environment.
use_latex : string, bool, or None, default=None
If ``True``, use default LaTeX rendering in GUI interfaces (png and
mathjax);
if ``False``, do not use LaTeX rendering;
if ``None``, make a guess based on the environment;
if ``'png'``, enable LaTeX rendering with an external LaTeX compiler,
falling back to matplotlib if external compilation fails;
if ``'matplotlib'``, enable LaTeX rendering with matplotlib;
if ``'mathjax'``, enable LaTeX text generation, for example MathJax
rendering in IPython notebook or text rendering in LaTeX documents;
if ``'svg'``, enable LaTeX rendering with an external latex compiler,
no fallback
wrap_line : bool
If True, lines will wrap at the end; if False, they will not wrap
but continue as one line. This is only relevant if ``pretty_print`` is
True.
num_columns : int or None, default=None
If ``int``, number of columns before wrapping is set to num_columns; if
``None``, number of columns before wrapping is set to terminal width.
This is only relevant if ``pretty_print`` is ``True``.
no_global : bool, default=False
If ``True``, the settings become system wide;
if ``False``, use just for this console/session.
ip : An interactive console
This can either be an instance of IPython,
or a class that derives from code.InteractiveConsole.
euler : bool, optional, default=False
Loads the euler package in the LaTeX preamble for handwritten style
fonts (https://www.ctan.org/pkg/euler).
forecolor : string or None, optional, default=None
DVI setting for foreground color. ``None`` means that either ``'Black'``,
``'White'``, or ``'Gray'`` will be selected based on a guess of the IPython
terminal color setting. See notes.
backcolor : string, optional, default='Transparent'
DVI setting for background color. See notes.
fontsize : string or int, optional, default='10pt'
A font size to pass to the LaTeX documentclass function in the
preamble. Note that the options are limited by the documentclass.
Consider using scale instead.
latex_mode : string, optional, default='plain'
The mode used in the LaTeX printer. Can be one of:
``{'inline'|'plain'|'equation'|'equation*'}``.
print_builtin : boolean, optional, default=True
If ``True`` then floats and integers will be printed. If ``False`` the
printer will only print SymPy types.
str_printer : function, optional, default=None
A custom string printer function. This should mimic
:func:`~.sstrrepr`.
pretty_printer : function, optional, default=None
A custom pretty printer. This should mimic :func:`~.pretty`.
latex_printer : function, optional, default=None
A custom LaTeX printer. This should mimic :func:`~.latex`.
scale : float, optional, default=1.0
Scale the LaTeX output when using the ``'png'`` or ``'svg'`` backends.
Useful for high dpi screens.
settings :
Any additional settings for the ``latex`` and ``pretty`` commands can
be used to fine-tune the output.
Examples
========
>>> from sympy.interactive import init_printing
>>> from sympy import Symbol, sqrt
>>> from sympy.abc import x, y
>>> sqrt(5)
sqrt(5)
>>> init_printing(pretty_print=True) # doctest: +SKIP
>>> sqrt(5) # doctest: +SKIP
___
\/ 5
>>> theta = Symbol('theta') # doctest: +SKIP
>>> init_printing(use_unicode=True) # doctest: +SKIP
>>> theta # doctest: +SKIP
\u03b8
>>> init_printing(use_unicode=False) # doctest: +SKIP
>>> theta # doctest: +SKIP
theta
>>> init_printing(order='lex') # doctest: +SKIP
>>> str(y + x + y**2 + x**2) # doctest: +SKIP
x**2 + x + y**2 + y
>>> init_printing(order='grlex') # doctest: +SKIP
>>> str(y + x + y**2 + x**2) # doctest: +SKIP
x**2 + x + y**2 + y
>>> init_printing(order='grevlex') # doctest: +SKIP
>>> str(y * x**2 + x * y**2) # doctest: +SKIP
x**2*y + x*y**2
>>> init_printing(order='old') # doctest: +SKIP
>>> str(x**2 + y**2 + x + y) # doctest: +SKIP
x**2 + x + y**2 + y
>>> init_printing(num_columns=10) # doctest: +SKIP
>>> x**2 + x + y**2 + y # doctest: +SKIP
x + y +
x**2 + y**2
Notes
=====
The foreground and background colors can be selected when using ``'png'`` or
``'svg'`` LaTeX rendering. Note that before the ``init_printing`` command is
executed, the LaTeX rendering is handled by the IPython console and not SymPy.
The colors can be selected among the 68 standard colors known to ``dvips``,
for a list see [1]_. In addition, the background color can be
set to ``'Transparent'`` (which is the default value).
When using the ``'Auto'`` foreground color, the guess is based on the
``colors`` variable in the IPython console, see [2]_. Hence, if
that variable is set correctly in your IPython console, there is a high
chance that the output will be readable, although manual settings may be
needed.
References
==========
.. [1] https://en.wikibooks.org/wiki/LaTeX/Colors#The_68_standard_colors_known_to_dvips
.. [2] https://ipython.readthedocs.io/en/stable/config/details.html#terminal-colors
See Also
========
sympy.printing.latex
sympy.printing.pretty
"""
import sys
from sympy.printing.printer import Printer
if pretty_print:
if pretty_printer is not None:
stringify_func = pretty_printer
else:
from sympy.printing import pretty as stringify_func
else:
if str_printer is not None:
stringify_func = str_printer
else:
from sympy.printing import sstrrepr as stringify_func
# Even if ip is not passed, double check that not in IPython shell
in_ipython = False
if ip is None:
try:
ip = get_ipython()
except NameError:
pass
else:
in_ipython = (ip is not None)
if ip and not in_ipython:
in_ipython = _is_ipython(ip)
if in_ipython and pretty_print:
try:
from IPython.terminal.interactiveshell import TerminalInteractiveShell
from code import InteractiveConsole
except ImportError:
pass
else:
# This will be True if we are in the qtconsole or notebook
if not isinstance(ip, (InteractiveConsole, TerminalInteractiveShell)) \
and 'ipython-console' not in ''.join(sys.argv):
if use_unicode is None:
debug("init_printing: Setting use_unicode to True")
use_unicode = True
if use_latex is None:
debug("init_printing: Setting use_latex to True")
use_latex = True
if not NO_GLOBAL and not no_global:
Printer.set_global_settings(order=order, use_unicode=use_unicode,
wrap_line=wrap_line, num_columns=num_columns)
else:
_stringify_func = stringify_func
if pretty_print:
stringify_func = lambda expr, **settings: \
_stringify_func(expr, order=order,
use_unicode=use_unicode,
wrap_line=wrap_line,
num_columns=num_columns,
**settings)
else:
stringify_func = \
lambda expr, **settings: _stringify_func(
expr, order=order, **settings)
if in_ipython:
mode_in_settings = settings.pop("mode", None)
if mode_in_settings:
debug("init_printing: Mode is not able to be set due to internals"
"of IPython printing")
_init_ipython_printing(ip, stringify_func, use_latex, euler,
forecolor, backcolor, fontsize, latex_mode,
print_builtin, latex_printer, scale,
**settings)
else:
_init_python_printing(stringify_func, **settings)