change column error

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-22-d50f7c5123c7> in <module>()
      1 for dataset in full_data:
      2     for k, label in enumerate(train['MSZoning'].unique()):
----> 3         dataset['MSZoning'] = dataset['MSZoning'].map({label: k}).astype(int)

c:\program files\python36\lib\site-packages\pandas\util\_decorators.py in wrapper(*args, **kwargs)
    176                 else:
    177                     kwargs[new_arg_name] = new_arg_value
--> 178             return func(*args, **kwargs)
    179         return wrapper
    180     return _deprecate_kwarg

c:\program files\python36\lib\site-packages\pandas\core\generic.py in astype(self, dtype, copy, errors, **kwargs)
   4999             # else, only a single dtype is given
   5000             new_data = self._data.astype(dtype=dtype, copy=copy, errors=errors,
-> 5001                                          **kwargs)
   5002             return self._constructor(new_data).__finalize__(self)
   5003

c:\program files\python36\lib\site-packages\pandas\core\internals.py in astype(self, dtype, **kwargs)
   3712
   3713     def astype(self, dtype, **kwargs):
-> 3714         return self.apply('astype', dtype=dtype, **kwargs)
   3715
   3716     def convert(self, **kwargs):

c:\program files\python36\lib\site-packages\pandas\core\internals.py in apply(self, f, axes, filter, do_integrity_check, consolidate, **kwargs)
   3579
   3580             kwargs['mgr'] = self
-> 3581             applied = getattr(b, f)(**kwargs)
   3582             result_blocks = _extend_blocks(applied, result_blocks)
   3583

c:\program files\python36\lib\site-packages\pandas\core\internals.py in astype(self, dtype, copy, errors, values, **kwargs)
    573     def astype(self, dtype, copy=False, errors='raise', values=None, **kwargs):
    574         return self._astype(dtype, copy=copy, errors=errors, values=values,
--> 575                             **kwargs)
    576
    577     def _astype(self, dtype, copy=False, errors='raise', values=None,

c:\program files\python36\lib\site-packages\pandas\core\internals.py in _astype(self, dtype, copy, errors, values, klass, mgr, **kwargs)
    662
    663                 # _astype_nansafe works fine with 1-d only
--> 664                 values = astype_nansafe(values.ravel(), dtype, copy=True)
    665                 values = values.reshape(self.shape)
    666

c:\program files\python36\lib\site-packages\pandas\core\dtypes\cast.py in astype_nansafe(arr, dtype, copy)
    700
    701         if not np.isfinite(arr).all():
--> 702             raise ValueError('Cannot convert non-finite values (NA or inf) to '
    703                              'integer')
    704

ValueError: Cannot convert non-finite values (NA or inf) to integer