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- import numpy as np
- import pytest
- import pandas as pd
- from pandas.core.interchange.utils import dtype_to_arrow_c_fmt
- # TODO: use ArrowSchema to get reference C-string.
- # At the time, there is no way to access ArrowSchema holding a type format string
- # from python. The only way to access it is to export the structure to a C-pointer,
- # see DataType._export_to_c() method defined in
- # https://github.com/apache/arrow/blob/master/python/pyarrow/types.pxi
- @pytest.mark.parametrize(
- "pandas_dtype, c_string",
- [
- (np.dtype("bool"), "b"),
- (np.dtype("int8"), "c"),
- (np.dtype("uint8"), "C"),
- (np.dtype("int16"), "s"),
- (np.dtype("uint16"), "S"),
- (np.dtype("int32"), "i"),
- (np.dtype("uint32"), "I"),
- (np.dtype("int64"), "l"),
- (np.dtype("uint64"), "L"),
- (np.dtype("float16"), "e"),
- (np.dtype("float32"), "f"),
- (np.dtype("float64"), "g"),
- (pd.Series(["a"]).dtype, "u"),
- (
- pd.Series([0]).astype("datetime64[ns]").dtype,
- "tsn:",
- ),
- (pd.CategoricalDtype(["a"]), "l"),
- (np.dtype("O"), "u"),
- ],
- )
- def test_dtype_to_arrow_c_fmt(pandas_dtype, c_string): # PR01
- """Test ``dtype_to_arrow_c_fmt`` utility function."""
- assert dtype_to_arrow_c_fmt(pandas_dtype) == c_string
- @pytest.mark.parametrize(
- "pa_dtype, args_kwargs, c_string",
- [
- ["null", {}, "n"],
- ["bool_", {}, "b"],
- ["uint8", {}, "C"],
- ["uint16", {}, "S"],
- ["uint32", {}, "I"],
- ["uint64", {}, "L"],
- ["int8", {}, "c"],
- ["int16", {}, "S"],
- ["int32", {}, "i"],
- ["int64", {}, "l"],
- ["float16", {}, "e"],
- ["float32", {}, "f"],
- ["float64", {}, "g"],
- ["string", {}, "u"],
- ["binary", {}, "z"],
- ["time32", ("s",), "tts"],
- ["time32", ("ms",), "ttm"],
- ["time64", ("us",), "ttu"],
- ["time64", ("ns",), "ttn"],
- ["date32", {}, "tdD"],
- ["date64", {}, "tdm"],
- ["timestamp", {"unit": "s"}, "tss:"],
- ["timestamp", {"unit": "ms"}, "tsm:"],
- ["timestamp", {"unit": "us"}, "tsu:"],
- ["timestamp", {"unit": "ns"}, "tsn:"],
- ["timestamp", {"unit": "ns", "tz": "UTC"}, "tsn:UTC"],
- ["duration", ("s",), "tDs"],
- ["duration", ("ms",), "tDm"],
- ["duration", ("us",), "tDu"],
- ["duration", ("ns",), "tDn"],
- ["decimal128", {"precision": 4, "scale": 2}, "d:4,2"],
- ],
- )
- def test_dtype_to_arrow_c_fmt_arrowdtype(pa_dtype, args_kwargs, c_string):
- # GH 52323
- pa = pytest.importorskip("pyarrow")
- if not args_kwargs:
- pa_type = getattr(pa, pa_dtype)()
- elif isinstance(args_kwargs, tuple):
- pa_type = getattr(pa, pa_dtype)(*args_kwargs)
- else:
- pa_type = getattr(pa, pa_dtype)(**args_kwargs)
- arrow_type = pd.ArrowDtype(pa_type)
- assert dtype_to_arrow_c_fmt(arrow_type) == c_string
|
