"""Tools for setting up printing in interactive sessions. """
from __future__ import print_function, division
import sys
from distutils.version import LooseVersion as V
from io import BytesIO
from sympy import latex as default_latex
from sympy import preview
from sympy.core.compatibility import integer_types
from sympy.utilities.misc import debug
def _init_python_printing(stringify_func, **settings):
"""Setup printing in Python interactive session. """
import sys
from sympy.core.compatibility import builtins
def _displayhook(arg):
"""Python's pretty-printer display hook.
This function was adapted from:
http://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, **settings):
"""Setup printing in IPython interactive session. """
try:
from IPython.lib.latextools import latex_to_png
except ImportError:
pass
preamble = "\\documentclass[%s]{article}\n" \
"\\pagestyle{empty}\n" \
"\\usepackage{amsmath,amsfonts}%s\\begin{document}"
if euler:
addpackages = '\\usepackage{euler}'
else:
addpackages = ''
preamble = preamble % (fontsize, addpackages)
imagesize = 'tight'
offset = "0cm,0cm"
resolution = 150
dvi = r"-T %s -D %d -bg %s -fg %s -O %s" % (
imagesize, resolution, backcolor, forecolor, offset)
dvioptions = dvi.split()
debug("init_printing: DVIOPTIONS:", dvioptions)
debug("init_printing: PREAMBLE:", preamble)
latex = latex_printer or default_latex
def _print_plain(arg, p, cycle):
"""caller for pretty, for use in IPython 0.11"""
if _can_print_latex(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',
outputbuffer=exprbuffer, preamble=preamble,
dvioptions=dvioptions)
except Exception as e:
# IPython swallows exceptions
debug("png printing:", "_preview_wrapper exception raised:",
repr(e))
raise
return exprbuffer.getvalue()
def _matplotlib_wrapper(o):
# mathtext does not understand certain latex flags, so we try to
# replace them with suitable subs
o = o.replace(r'\operatorname', '')
o = o.replace(r'\overline', r'\bar')
# 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:
return latex_to_png(o)
except ValueError as e:
debug('matplotlib exception caught:', repr(e))
return None
def _can_print_latex(o):
"""Return True if type o can be printed with LaTeX.
If o is a container type, this is True if and only if every element of
o can be printed with LaTeX.
"""
from sympy import Basic
from sympy.matrices import MatrixBase
from sympy.physics.vector import Vector, Dyadic
if isinstance(o, (list, tuple, set, frozenset)):
return all(_can_print_latex(i) for i in o)
elif isinstance(o, dict):
return all(_can_print_latex(i) and _can_print_latex(o[i]) for i in o)
elif isinstance(o, bool):
return False
# TODO : Investigate if "elif hasattr(o, '_latex')" is more useful
# to use here, than these explicit imports.
elif isinstance(o, (Basic, MatrixBase, Vector, Dyadic)):
return True
elif isinstance(o, (float, integer_types)) and print_builtin:
return True
return False
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_latex(o):
s = latex(o, mode=latex_mode, **settings)
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_matplotlib(o):
"""
A function that returns a png rendered by mathtext
"""
if _can_print_latex(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_latex(o):
s = latex(o, mode='plain', **settings)
s = s.replace(r'\dag', r'\dagger')
s = s.strip('$')
return '$$%s$$' % s
def _result_display(self, arg):
"""IPython's pretty-printer display hook, for use in IPython 0.10
This function was adapted from:
ipython/IPython/hooks.py:155
"""
if self.rc.pprint:
out = stringify_func(arg)
if '\n' in out:
print
print(out)
else:
print(repr(arg))
import IPython
if V(IPython.__version__) >= '0.11':
from sympy.core.basic import Basic
from sympy.matrices.matrices import MatrixBase
from sympy.physics.vector import Vector, Dyadic
printable_types = [Basic, MatrixBase, float, tuple, list, set,
frozenset, dict, Vector, Dyadic] + list(integer_types)
plaintext_formatter = ip.display_formatter.formatters['text/plain']
for cls in printable_types:
plaintext_formatter.for_type(cls, _print_plain)
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)
elif use_latex == 'matplotlib':
debug("init_printing: using matplotlib formatter")
for cls in printable_types:
png_formatter.for_type(cls, _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)
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)
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)
else:
ip.set_hook('result_display', _result_display)
def _is_ipython(shell):
"""Is a shell instance an IPython shell?"""
# shortcut, so we don't import IPython if we don't have to
if 'IPython' not in sys.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)
[docs]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='Black',
backcolor='Transparent', fontsize='10pt',
latex_mode='equation*', print_builtin=True,
str_printer=None, pretty_printer=None,
latex_printer=None, **settings):
"""
Initializes pretty-printer depending on the environment.
Parameters
==========
pretty_print: boolean
If True, use pretty_print to stringify or the provided pretty
printer; if False, use sstrrepr to stringify or the provided string
printer.
order: string or None
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: boolean or None
If True, use unicode characters;
if False, do not use unicode characters.
use_latex: string, boolean, or None
If True, use default latex rendering in GUI interfaces (png and
mathjax);
if False, do not use latex rendering;
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
wrap_line: boolean
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
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: boolean
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: boolean, optional, default=False
Loads the euler package in the LaTeX preamble for handwritten style
fonts (http://www.ctan.org/pkg/euler).
forecolor: string, optional, default='Black'
DVI setting for foreground color.
backcolor: string, optional, default='Transparent'
DVI setting for background color.
fontsize: string, optional, default='10pt'
A font size to pass to the LaTeX documentclass function in the
preamble.
latex_mode: string, optional, default='equation*'
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
sympy.printing.sstrrepr().
pretty_printer: function, optional, default=None
A custom pretty printer. This should mimic sympy.printing.pretty().
latex_printer: function, optional, default=None
A custom LaTeX printer. This should mimic sympy.printing.latex().
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
"""
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:
import IPython
# IPython 1.0 deprecates the frontend module, so we import directly
# from the terminal module to prevent a deprecation message from being
# shown.
if V(IPython.__version__) >= '1.0':
from IPython.terminal.interactiveshell import TerminalInteractiveShell
else:
from IPython.frontend.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:
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: \
_stringify_func(expr, order=order,
use_unicode=use_unicode,
wrap_line=wrap_line,
num_columns=num_columns)
else:
stringify_func = lambda expr: _stringify_func(expr, order=order)
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, **settings)
else:
_init_python_printing(stringify_func, **settings)
