TypeError: Not JSON Serializable

[junjer]

When try to import HeraCallback get this error

from heraspy.model import HeraModel Traceback (most recent call last): File "C:\Program Files\Anaconda3\lib\site-packages\IPython\core\interactiveshell.py", line 2881, in run_code exec(code_obj, self.user_global_ns, self.user_ns) File "<ipython-input-13-0afb57adc2e7>", line 1, in <module> from heraspy.model import HeraModel File "C:\Program Files\JetBrains\PyCharm Community Edition 2017.1.1\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import module = self._system_import(name, *args, **kwargs) File "C:\Program Files\Anaconda3\lib\site-packages\heraspy\model.py", line 1, in <module> from heraspy.callback import HeraCallback File "C:\Program Files\JetBrains\PyCharm Community Edition 2017.1.1\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import module = self._system_import(name, *args, **kwargs) File "C:\Program Files\Anaconda3\lib\site-packages\heraspy\callback.py", line 20, in <module> raise TypeError('Not JSON Serializable') TypeError: Not JSON Serializable