<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def astype(self, dtype, copy=True):
 """ Coerce this type to another dtype Parameters dtype : numpy dtype or pandas type copy : bool, default True By default, astype always returns a newly allocated object. If copy is set to False and dtype is categorical, the original object is returned. .. versionadded:: 0.19.0 """

        if is_categorical_dtype(dtype):
            # GH 10696/18593
            dtype = self.dtype.update_dtype(dtype)
            self = self.copy() if copy else self
            if dtype == self.dtype:
                return self
            return self._set_dtype(dtype)
        return np.array(self, dtype=dtype, copy=copy)