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- """
- Includes test for last_valid_index.
- """
- import numpy as np
- import pytest
- from pandas import (
- DataFrame,
- Series,
- )
- import pandas._testing as tm
- class TestFirstValidIndex:
- def test_first_valid_index_single_nan(self, frame_or_series):
- # GH#9752 Series/DataFrame should both return None, not raise
- obj = frame_or_series([np.nan])
- assert obj.first_valid_index() is None
- assert obj.iloc[:0].first_valid_index() is None
- @pytest.mark.parametrize(
- "empty", [DataFrame(), Series(dtype=object), Series([], index=[], dtype=object)]
- )
- def test_first_valid_index_empty(self, empty):
- # GH#12800
- assert empty.last_valid_index() is None
- assert empty.first_valid_index() is None
- @pytest.mark.parametrize(
- "data,idx,expected_first,expected_last",
- [
- ({"A": [1, 2, 3]}, [1, 1, 2], 1, 2),
- ({"A": [1, 2, 3]}, [1, 2, 2], 1, 2),
- ({"A": [1, 2, 3, 4]}, ["d", "d", "d", "d"], "d", "d"),
- ({"A": [1, np.nan, 3]}, [1, 1, 2], 1, 2),
- ({"A": [np.nan, np.nan, 3]}, [1, 1, 2], 2, 2),
- ({"A": [1, np.nan, 3]}, [1, 2, 2], 1, 2),
- ],
- )
- def test_first_last_valid_frame(self, data, idx, expected_first, expected_last):
- # GH#21441
- df = DataFrame(data, index=idx)
- assert expected_first == df.first_valid_index()
- assert expected_last == df.last_valid_index()
- @pytest.mark.parametrize("index_func", [tm.makeStringIndex, tm.makeDateIndex])
- def test_first_last_valid(self, index_func):
- N = 30
- index = index_func(N)
- mat = np.random.randn(N)
- mat[:5] = np.nan
- mat[-5:] = np.nan
- frame = DataFrame({"foo": mat}, index=index)
- assert frame.first_valid_index() == frame.index[5]
- assert frame.last_valid_index() == frame.index[-6]
- ser = frame["foo"]
- assert ser.first_valid_index() == frame.index[5]
- assert ser.last_valid_index() == frame.index[-6]
- @pytest.mark.parametrize("index_func", [tm.makeStringIndex, tm.makeDateIndex])
- def test_first_last_valid_all_nan(self, index_func):
- # GH#17400: no valid entries
- index = index_func(30)
- frame = DataFrame(np.nan, columns=["foo"], index=index)
- assert frame.last_valid_index() is None
- assert frame.first_valid_index() is None
- ser = frame["foo"]
- assert ser.first_valid_index() is None
- assert ser.last_valid_index() is None
|
