Render Sympy Expression as graphical tree inside IPython notebook

render_sympy_tree.py

def render_sympy_tree(expr):
    """Render the given Sympy Expression as a graphical tree, inside an IPython notebook"""
    from sympy.printing.dot import dotprint
    import tempfile
    import subprocess
    import os
    from IPython.display import SVG 
    with tempfile.NamedTemporaryFile(mode='w', delete=False) as out_fh:
        out_fh.write(dotprint(expr))
    subprocess.run(['/usr/bin/dot', '-Tsvg', out_fh.name, '-o', out_fh.name + ".svg"])
    svg = SVG(filename=(out_fh.name + ".svg"))
    os.unlink(out_fh.name)
    os.unlink(out_fh.name + ".svg")
    return svg

I'm having problems with dot inside a conda environment (due to #1357), which also breaks the graphviz package. The above code solves the problem of rendering the graphviz tree representation of Sympy expressions in Python 3.5, via a temporary file. Note the use of the system /usr/bin/dot instead of just dot (which would refer to the broken binary that's installed by conda).