test_retain_attributes.py

from warnings import catch_warnings

import pytest

from pandas._libs.tslibs import Timestamp

from pandas import (
    DataFrame,
    Series,
    _testing as tm,
    date_range,
    read_hdf,
)
from pandas.tests.io.pytables.common import (
    _maybe_remove,
    ensure_clean_path,
    ensure_clean_store,
)

pytestmark = pytest.mark.single


def test_retain_index_attributes(setup_path):

    # GH 3499, losing frequency info on index recreation
    df = DataFrame(
        {"A": Series(range(3), index=date_range("2000-1-1", periods=3, freq="H"))}
    )

    with ensure_clean_store(setup_path) as store:
        _maybe_remove(store, "data")
        store.put("data", df, format="table")

        result = store.get("data")
        tm.assert_frame_equal(df, result)

        for attr in ["freq", "tz", "name"]:
            for idx in ["index", "columns"]:
                assert getattr(getattr(df, idx), attr, None) == getattr(
                    getattr(result, idx), attr, None
                )

        # try to append a table with a different frequency
        with catch_warnings(record=True):
            df2 = DataFrame(
                {
                    "A": Series(
                        range(3), index=date_range("2002-1-1", periods=3, freq="D")
                    )
                }
            )
            store.append("data", df2)

        assert store.get_storer("data").info["index"]["freq"] is None

        # this is ok
        _maybe_remove(store, "df2")
        df2 = DataFrame(
            {
                "A": Series(
                    range(3),
                    index=[
                        Timestamp("20010101"),
                        Timestamp("20010102"),
                        Timestamp("20020101"),
                    ],
                )
            }
        )
        store.append("df2", df2)
        df3 = DataFrame(
            {"A": Series(range(3), index=date_range("2002-1-1", periods=3, freq="D"))}
        )
        store.append("df2", df3)


@pytest.mark.filterwarnings(
    "ignore:\\nthe :pandas.io.pytables.AttributeConflictWarning"
)
def test_retain_index_attributes2(setup_path):
    with ensure_clean_path(setup_path) as path:

        with catch_warnings(record=True):

            df = DataFrame(
                {
                    "A": Series(
                        range(3), index=date_range("2000-1-1", periods=3, freq="H")
                    )
                }
            )
            df.to_hdf(path, "data", mode="w", append=True)
            df2 = DataFrame(
                {
                    "A": Series(
                        range(3), index=date_range("2002-1-1", periods=3, freq="D")
                    )
                }
            )

            df2.to_hdf(path, "data", append=True)

            idx = date_range("2000-1-1", periods=3, freq="H")
            idx.name = "foo"
            df = DataFrame({"A": Series(range(3), index=idx)})
            df.to_hdf(path, "data", mode="w", append=True)

        assert read_hdf(path, "data").index.name == "foo"

        with catch_warnings(record=True):

            idx2 = date_range("2001-1-1", periods=3, freq="H")
            idx2.name = "bar"
            df2 = DataFrame({"A": Series(range(3), index=idx2)})
            df2.to_hdf(path, "data", append=True)

        assert read_hdf(path, "data").index.name is None