def _astype_nansafe(arr, dtype, copy=True): """ return a view if copy is False, but need to be very careful as the result shape could change! """ if not isinstance(dtype, np.dtype): dtype = _coerce_to_dtype(dtype) if issubclass(dtype.type, text_type): # in Py3 that's str, in Py2 that's unicode return lib.astype_unicode(arr.ravel()).reshape(arr.shape) elif issubclass(dtype.type, string_types): return lib.astype_str(arr.ravel()).reshape(arr.shape) elif is_datetime64_dtype(arr): if dtype == object: return tslib.ints_to_pydatetime(arr.view(np.int64)) elif dtype == np.int64: return arr.view(dtype) elif dtype != _NS_DTYPE: raise TypeError("cannot astype a datetimelike from [%s] to [%s]" % (arr.dtype, dtype)) return arr.astype(_NS_DTYPE) elif is_timedelta64_dtype(arr): if dtype == np.int64: return arr.view(dtype) elif dtype == object: return tslib.ints_to_pytimedelta(arr.view(np.int64)) # in py3, timedelta64[ns] are int64 elif ((PY3 and dtype not in [_INT64_DTYPE, _TD_DTYPE]) or (not PY3 and dtype != _TD_DTYPE)): # allow frequency conversions if dtype.kind == 'm': mask = isnull(arr) result = arr.astype(dtype).astype(np.float64) result[mask] = np.nan return result raise TypeError("cannot astype a timedelta from [%s] to [%s]" % (arr.dtype, dtype)) return arr.astype(_TD_DTYPE) elif (np.issubdtype(arr.dtype, np.floating) and np.issubdtype(dtype, np.integer)): if not np.isfinite(arr).all(): raise ValueError('Cannot convert non-finite values (NA or inf) to ' 'integer') elif arr.dtype == np.object_ and np.issubdtype(dtype.type, np.integer): # work around NumPy brokenness, #1987 return lib.astype_intsafe(arr.ravel(), dtype).reshape(arr.shape) if copy: return arr.astype(dtype) return arr.view(dtype)