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@BekeJ /
Last active May 25, 2016

IPython notebook py2tex
Module for IPython to display code with TeX representation.
This makes for example the following workflow possible:
.. sourcecode:: ipython
In [1]: %load_ext py2tex
In [2]: from math import *
In [3]: %tex (1+sqrt(5))/2
(1+sqrt(5))/2 = 1.618
In [4]: %%tex a = 1.0
...: b=3.0
...: c = sqrt(a**2+b**2)
a = 1.0
c = sqrt(a**2+b**2) = 3.162
In [5]: %texformat %.3e
In [6]: %tex e**10
e**10 = 2.203 \cdot 10^{4}
In [7]: %texnr c = sqrt(a**2+b**2)
c = sqrt(a**2+b**2)
When IPython TeX rendering is enabled, the results are displayed with TeX !!!
The following magic commands are provided:
One line TeX conversion with result output.
Multi line TeX conversion with result output.
One line TeX conversion without result output.
Multi line TeX conversion without result output.
Set the output format. (e.g. %.3f)
- Only true mathematical lines are supported for now
- Usage of underscores in variable names will result in subscript.
First _ will be subscript, all other _ will be converted to a ,
- greek letters as variable name are converted to their TeX equivalent
- Usage of the Unum class for unit-ware calculations is supported.
- when unum objects are used, %%tex detects when the expression must be printed
eg. v = 10*m/s is not displayed like v = 10*m/s = 10 m/s as in previous versions
Version history
release 0.2:
- units in expressions are not displayed with italic font
- variable are always italic font
- %%tex knows when the expression is an assignment with units only
release 0.1:
- initial version
import ast
from IPython.core.display import Latex
from IPython.core.magic import (Magics, magics_class, line_magic,
cell_magic, line_cell_magic)
from IPython.core.displaypub import publish_display_data
import re
import unum #
#Version: 0.2
# All GPLv3 except the class LatexVisitor which is cc by-sa 3.0 as it is based
# upon a snippet from stackoverflow (
#Hosted as a Gist:
# Beke, J.
class PrettyPrint(Magics):
"""Defines IPython magic function for LaTeX output of simple expressions"""
outputFormat = "%.3f"
greekLetters = {'Alpha': '\\Alpha',
'Beta': '\\Beta',
'Chi': '\\Chi',
'Delta': '\\Delta',
'Epsilon': '\\Epsilon',
'Eta': '\\Eta',
'Gamma': '\\Gamma',
'Iota': '\\Iota',
'Kappa': '\\Kappa',
'Lambda': '\\Lambda',
'Mu': '\\Mu',
'Nu': '\\Nu',
'Omega': '\\Omega',
'Phi': '\\Phi',
'Pi': '\\Pi',
'Psi': '\\Psi',
'Rho': '\\Rho',
'Sigma': '\\Sigma',
'Tau': '\\Tau',
'Theta': '\\Theta',
'Upsilon': '\\Upsilon',
'Xi': '\\Xi',
'Zeta': '\\Zeta',
'alpha': '\\alpha',
'beta': '\\beta',
'chi': '\\chi',
'delta': '\\delta',
'epsilon': '\\epsilon',
'eta': '\\eta',
'gamma': '\\gamma',
'varphi': '\\varphi',
'iota': '\\iota',
'kappa': '\\kappa',
'lambda': '\\lambda',
'mu': '\\mu',
'nu': '\\nu',
'omega': '\\omega',
'phi': '\\phi',
'pi': '\\pi',
'psi': '\\psi',
'rho': '\\rho',
'sigma': '\\sigma',
'tau': '\\tau',
'theta': '\\theta',
'upsilon': '\\upsilon',
'varepsilon': '\\varepsilon',
'varkappa': '\\varkappa',
'varphi': '\\varphi',
'varpi': '\\varpi',
'varrho': '\\varrho',
'varsigma': '\\varsigma',
'vartheta': '\\vartheta',
'xi': '\\xi',
'zeta': '\\zeta'}
def __init__(self, shell):
super(PrettyPrint, self).__init__(shell)
def tex(self, line, cell= None):
"""Cell and line magic %tex"""
#always do first line
#in case of cellmagic (with %%tex)
if not (cell is None):
for cline in cell.split("\n"):
if len(cline)>0:
def texnr(self, line, cell= None):
"""Cell and line magic %texnr"""
#always do first line
#in case of cellmagic (with %%tex)
if not (cell is None):
for cline in cell.split("\n"):
if len(cline)>0:
def texformat(self, line):
"""cell magic to set the result format string"""
arg = line.strip(" \t")
temp = arg % 3.1415
self.outputFormat = line.strip(" \t")
except ValueError:
raise ValueError(arg + " is not supported")
def doLine(self,line,no_result = False):
"""Method to convert and print one line
#check for assignment
i = line.find("=")
if i<0 or line[i+1]=='=':
# no assignment : print expression = result
result =
{'text/latex': "$$"+self.py2tex(line)+" = "+self.numericToString(result)+"$$",
'text/plain': line+" = "+self.numericToString(result)})
# expression was assignment
variable = line[:i].strip()
expression = line[i+1:].strip()
result ={variable: result})
temp = re.findall('[-+]?\d*\.\d+[eE][-+]?\d+|[-+]?\d*\.\d+|[-+]?\d+', expression.strip())
# assignment: variable = number
{'text/latex': "$$"+self.parseVariable(variable.strip())+" = "+self.py2tex(expression)+"$$",
'text/plain': line})
except ValueError:
if no_result:
# assignment: variable = expression
{'text/latex': "$$"+self.parseVariable(variable.strip())+" = "+self.py2tex(expression)+"$$",
'text/plain': line})
# assignment: variable = expression = number
# unit is always an expression so test first
if self.isUnumAssignment(expression):
#unit assignment, print only result
{'text/latex': "$$"+self.parseVariable(variable.strip())+" = "+self.numericToString("$$",
'text/plain': line+" = "+self.numericToString(})
# assignment: variable = expression = number
{'text/latex': "$$"+self.parseVariable(variable.strip())+" = "+self.py2tex(expression)+" = "+self.numericToString("$$",
'text/plain': line+" = "+self.numericToString(})
def numericToString(self, number):
"""Convert a number to the defined string representation"""
if type(number) == unum.Unum:
a = self.outputFormat % number._value
unit = "\\;\\:%s" % self.prettyUnumUnit(number) #number.strUnit()[1:-1]
a = self.outputFormat % number
unit = ''
a = a.split("e")
if len(a)==1:
return a[0] + unit
if int(a[1]) != 0:
return "%s \\cdot 10^{%s} %s" % (a[0], int(a[1]), unit)
return a[0] + unit
def py2tex(self, expr):
"""Actual expression to TeX conversion"""
pt = ast.parse(expr)
return LatexVisitor().visit(pt.body[0].value)
def parseVariable(self, name):
"""Convert a variable to greek letters and parse the _ to subscript or comma"""
#parse greek letters
name = name.split("_")
for i in range(len(name)):
if self.greekLetters.has_key(name[i]):
name[i] = self.greekLetters[name[i]]
#first part as mbox
#if name[0].find("\\") < 0:
# name[0] = "\\mbox{%s}" % name[0]
#parse underscore and comma
if len(name)>1:
return name[0]+"_{"+','.join(name[1:])+"}"
return name[0]
def prettyUnumUnit(self,unum):
"""Pretty print a Unum unit object"""
n = ''
d = ''
for name,power in sorted(unum._unit.items()):
if power < 0:
if power ==-1:
d += "$\\mbox{%s}" % (name)
d += "$\\mbox{%s}^{%d}" % (name, power*-1)
if power == 1:
n += "$\\mbox{%s}" % (name)
n += "$\\mbox{%s}^{%d}" % (name, power)
if n=='':
n ='1'
if d =='':
if n=='1':
return ''
return n
return n+"/"+d
def isUnumAssignment(self,expression):
""" Check if the expression is an Unum assignment """
pos = expression.find("*")
if pos>=1:
number = expression[0:pos]
unit = expression[pos+1:]
# test if number is really a number
except ValueError:
# no unit assignment
return False
# try if unit part evaluated is of type unum and _value=1
result =
if type(result)==unum.Unum:
if result._value!=1:
# no unit assignment
return False
# no unit assignment
return False
# no * so no unit
return False
# if reached this statement, must be unum assignment
return True
class LatexVisitor(ast.NodeVisitor):
# based on source:
greekLetters = PrettyPrint.greekLetters
functions = {'arccos': '\\arccos',
'arcsin': '\\arcsin',
'arctan': '\\arctan',
'cos': '\\cos',
'cosh': '\\cosh',
'cot': '\\cot',
'coth': '\\coth',
'csc': '\\csc',
'ln': '\\ln',
'log': '\\log',
'max': '\\max',
'min': '\\min',
'sec': '\\sec',
'sin': '\\sin',
'sinh': '\\sinh',
'tan': '\\tan',
'tanh': '\\tanh'}
def prec(self, n):
return getattr(self, 'prec_'+n.__class__.__name__, getattr(self, 'generic_prec'))(n)
def visit_Call(self, n):
func = self.visit(n.func)
args = ', '.join(map(self.visit, n.args))
if func == 'sqrt':
return '\sqrt{%s}' % args
# parse know LaTeX functions
if self.functions.has_key(func):
return r'%s\left(%s\right)' % (self.functions[func], args)
return r'\mbox{%s}\left(%s\right)' % (func, args)
def prec_Call(self, n):
return 1000
def visit_Name(self, n):
#test if unum
result = get_ipython().ev(
if type(result) == unum.Unum:
if result._value==1:
return "\\mbox{%s}" %
#parse greek letters
name ="_")
for i in range(len(name)):
if self.greekLetters.has_key(name[i]):
name[i] = self.greekLetters[name[i]]
#parse underscore and comma
if len(name)>1:
return name[0]+"_{"+','.join(name[1:])+"}"
return name[0]
def prec_Name(self, n):
return 1000
def visit_UnaryOp(self, n):
if self.prec(n.op) > self.prec(n.operand):
return r'%s \left(%s\right)' % (self.visit(n.op), self.visit(n.operand))
return r'%s %s' % (self.visit(n.op), self.visit(n.operand))
def prec_UnaryOp(self, n):
return self.prec(n.op)
def visit_BinOp(self, n):
if self.prec(n.op) > self.prec(n.left):
left = r'\left(%s\right)' % self.visit(n.left)
left = self.visit(n.left)
if self.prec(n.op) > self.prec(n.right):
right = r'\left(%s\right)' % self.visit(n.right)
right = self.visit(n.right)
if isinstance(n.op, ast.Div):
return r'\frac{%s}{%s}' % (self.visit(n.left), self.visit(n.right))
elif isinstance(n.op, ast.FloorDiv):
return r'\left\lfloor\frac{%s}{%s}\right\rfloor' % (self.visit(n.left), self.visit(n.right))
elif isinstance(n.op, ast.Pow):
return r'%s^{%s}' % (left, self.visit(n.right))
return r'%s %s %s' % (left, self.visit(n.op), right)
def prec_BinOp(self, n):
return self.prec(n.op)
def visit_Sub(self, n):
return '-'
def prec_Sub(self, n):
return 300
def visit_Add(self, n):
return '+'
def prec_Add(self, n):
return 300
def visit_Mult(self, n):
return '\\cdot'
def prec_Mult(self, n):
return 400
def visit_Mod(self, n):
return '\\bmod'
def prec_Mod(self, n):
return 500
def prec_Pow(self, n):
return 700
def prec_Div(self, n):
return 400
def prec_FloorDiv(self, n):
return 400
def visit_LShift(self, n):
return '\\mbox{shiftLeft}'
def visit_RShift(self, n):
return '\\mbox{shiftRight}'
def visit_BitOr(self, n):
return '\\mbox{or}'
def visit_BitXor(self, n):
return '\\mbox{xor}'
def visit_BitAnd(self, n):
return '\\mbox{and}'
def visit_Invert(self, n):
return '\\mbox{invert}'
def prec_Invert(self, n):
return 800
def visit_Not(self, n):
return '\\neg'
def prec_Not(self, n):
return 800
def visit_UAdd(self, n):
return '+'
def prec_UAdd(self, n):
return 800
def visit_USub(self, n):
return '-'
def prec_USub(self, n):
return 800
def visit_Num(self, n):
#TODO: convert forms with e03 !
return str(n.n)
def prec_Num(self, n):
return 1000
def generic_visit(self, n):
#walk ???
if isinstance(n, ast.AST):
return r'' % (n.__class__.__name__, ', '.join(map(self.visit, [getattr(n, f) for f in n._fields])))
return str(n)
def generic_prec(self, n):
return 0
def load_ipython_extension(ip):
#register magic to hold state
magicPrettyPrint = PrettyPrint(ip)
# code below to be uncommented for testing code with
# simple "import py2tex" statement
#magicPrettyPrint = PrettyPrint(ip)
duccoder commented Jun 3, 2015

Hi, it's very nice. And I found repository of you: with new releases
And I has update your extension info:

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