def as_json_table_type(x): """ Convert a NumPy / pandas type to its corresponding json_table. Parameters ---------- x : array or dtype Returns ------- t : str the Table Schema data types Notes ----- This table shows the relationship between NumPy / pandas dtypes, and Table Schema dtypes. ============== ================= Pandas type Table Schema type ============== ================= int64 integer float64 number bool boolean datetime64[ns] datetime timedelta64[ns] duration object str categorical any =============== ================= """ if is_integer_dtype(x): return 'integer' elif is_bool_dtype(x): return 'boolean' elif is_numeric_dtype(x): return 'number' elif (is_datetime64_dtype(x) or is_datetime64tz_dtype(x) or is_period_dtype(x)): return 'datetime' elif is_timedelta64_dtype(x): return 'duration' elif is_categorical_dtype(x): return 'any' elif is_string_dtype(x): return 'string' else: return 'any'
def make_sparse(arr, kind='block', fill_value=None): """ Convert ndarray to sparse format Parameters ---------- arr : ndarray kind : {'block', 'integer'} fill_value : NaN or another value Returns ------- (sparse_values, index) : (ndarray, SparseIndex) """ arr = _sanitize_values(arr) if arr.ndim > 1: raise TypeError("expected dimension <= 1 data") if fill_value is None: fill_value = na_value_for_dtype(arr.dtype) if isnull(fill_value): mask = notnull(arr) else: # For str arrays in NumPy 1.12.0, operator!= below isn't # element-wise but just returns False if fill_value is not str, # so cast to object comparison to be safe if is_string_dtype(arr): arr = arr.astype(object) mask = arr != fill_value length = len(arr) if length != mask.size: # the arr is a SparseArray indices = mask.sp_index.indices else: indices = mask.nonzero()[0].astype(np.int32) index = _make_index(length, indices, kind) sparsified_values = arr[mask] return sparsified_values, index, fill_value
def test_not_string(self): # though PeriodDtype has object kind, it cannot be string self.assertFalse(is_string_dtype(PeriodDtype('D')))