---------------------------------------------------------------------------
CalledProcessError                        Traceback (most recent call last)
~\anaconda3.1\lib\site-packages\IPython\core\formatters.py in __call__(self, obj)
    343             method = get_real_method(obj, self.print_method)
    344             if method is not None:
--> 345                 return method()
    346             return None
    347         else:

~\anaconda3.1\lib\site-packages\graphviz\files.py in _repr_svg_(self)
    111 
    112     def _repr_svg_(self):
--> 113         return self.pipe(format='svg').decode(self._encoding)
    114 
    115     def pipe(self, format=None, renderer=None, formatter=None, quiet=False):

~\anaconda3.1\lib\site-packages\graphviz\files.py in pipe(self, format, renderer, formatter, quiet)
    136         out = backend.pipe(self._engine, format, data,
    137                            renderer=renderer, formatter=formatter,
--> 138                            quiet=quiet)
    139 
    140         return out

~\anaconda3.1\lib\site-packages\graphviz\backend.py in pipe(engine, format, data, renderer, formatter, quiet)
    242     """
    243     cmd, _ = command(engine, format, None, renderer, formatter)
--> 244     out, _ = run(cmd, input=data, capture_output=True, check=True, quiet=quiet)
    245     return out
    246 

~\anaconda3.1\lib\site-packages\graphviz\backend.py in run(cmd, input, capture_output, check, encoding, quiet, **kwargs)
    182     if check and proc.returncode:
    183         raise CalledProcessError(proc.returncode, cmd,
--> 184                                  output=out, stderr=err)
    185 
    186     return out, err

CalledProcessError: Command '['dot', '-Tsvg']' returned non-zero exit status 1. [stderr: b'Format: "svg" not recognized. Use one of:\r\n']