Related to #1359. Removing extra $ that older versions sympy add.

Older versions of sympy put in an extra $ when using
latex(e, mode='plain'). We are removing those before we add our
own to make sure it works.

IPython/extensions/sympyprinting.py

@@ -1,98 +1,99 b''
 """
 A print function that pretty prints sympy Basic objects.
 
 :moduleauthor: Brian Granger
 
 Usage
 =====
 
 Once the extension is loaded, Sympy Basic objects are automatically
 pretty-printed.
 
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from IPython.lib.latextools import latex_to_png
 from IPython.testing import decorators as dec
 # use @dec.skipif_not_sympy to skip tests requiring sympy
 
 try:
     from sympy import pretty, latex
 except ImportError:
     pass
 
 
 #-----------------------------------------------------------------------------
 # Definitions of magic functions for use with IPython
 #-----------------------------------------------------------------------------
 
 def print_basic_unicode(o, p, cycle):
     """A function to pretty print sympy Basic objects."""
     if cycle:
         return p.text('Basic(...)')
     out = pretty(o, use_unicode=True)
     if '\n' in out:
         p.text(u'\n')
     p.text(out)
 
 
 def print_png(o):
     """A function to display sympy expression using LaTex -> PNG."""
     s = latex(o, mode='inline')
     # mathtext does not understand certain latex flags, so we try to replace
     # them with suitable subs.
     s = s.replace('\\operatorname','')
     s = s.replace('\\overline', '\\bar')
     png = latex_to_png(s)
     return png
 
 
 def print_latex(o):
     """A function to generate the latex representation of sympy expressions."""
     s = latex(o, mode='plain')
     s = s.replace('\\dag','\\dagger')
+    s = s.strip('$')
     return '$$%s$$' % s
 
 
 _loaded = False
 
 def load_ipython_extension(ip):
     """Load the extension in IPython."""
     global _loaded
     if not _loaded:
         plaintext_formatter = ip.display_formatter.formatters['text/plain']
 
         for cls in (object, tuple, list, set, frozenset, dict, str):
             plaintext_formatter.for_type(cls, print_basic_unicode)
 
         plaintext_formatter.for_type_by_name(
             'sympy.core.basic', 'Basic', print_basic_unicode
         )
         plaintext_formatter.for_type_by_name(
             'sympy.matrices.matrices', 'Matrix', print_basic_unicode
         )
 
         png_formatter = ip.display_formatter.formatters['image/png']
 
         png_formatter.for_type_by_name(
             'sympy.core.basic', 'Basic', print_png
         )
 
         latex_formatter = ip.display_formatter.formatters['text/latex']
         latex_formatter.for_type_by_name(
             'sympy.core.basic', 'Basic', print_latex
         )
         latex_formatter.for_type_by_name(
             'sympy.matrices.matrices', 'Matrix', print_latex
         )
         _loaded = True