laywerrobot/lib/python3.6/site-packages/pandas/tests/categorical/test_missing.py
2020-08-27 21:55:39 +02:00

85 lines
3 KiB
Python

# -*- coding: utf-8 -*-
import collections
import numpy as np
import pytest
import pandas.util.testing as tm
from pandas import Categorical, Index, isna
from pandas.compat import lrange
from pandas.core.dtypes.dtypes import CategoricalDtype
class TestCategoricalMissing(object):
def test_na_flags_int_categories(self):
# #1457
categories = lrange(10)
labels = np.random.randint(0, 10, 20)
labels[::5] = -1
cat = Categorical(labels, categories, fastpath=True)
repr(cat)
tm.assert_numpy_array_equal(isna(cat), labels == -1)
def test_nan_handling(self):
# Nans are represented as -1 in codes
c = Categorical(["a", "b", np.nan, "a"])
tm.assert_index_equal(c.categories, Index(["a", "b"]))
tm.assert_numpy_array_equal(c._codes, np.array([0, 1, -1, 0],
dtype=np.int8))
c[1] = np.nan
tm.assert_index_equal(c.categories, Index(["a", "b"]))
tm.assert_numpy_array_equal(c._codes, np.array([0, -1, -1, 0],
dtype=np.int8))
# Adding nan to categories should make assigned nan point to the
# category!
c = Categorical(["a", "b", np.nan, "a"])
tm.assert_index_equal(c.categories, Index(["a", "b"]))
tm.assert_numpy_array_equal(c._codes, np.array([0, 1, -1, 0],
dtype=np.int8))
def test_set_dtype_nans(self):
c = Categorical(['a', 'b', np.nan])
result = c._set_dtype(CategoricalDtype(['a', 'c']))
tm.assert_numpy_array_equal(result.codes, np.array([0, -1, -1],
dtype='int8'))
def test_set_item_nan(self):
cat = Categorical([1, 2, 3])
cat[1] = np.nan
exp = Categorical([1, np.nan, 3], categories=[1, 2, 3])
tm.assert_categorical_equal(cat, exp)
@pytest.mark.parametrize('fillna_kwargs, msg', [
(dict(value=1, method='ffill'),
"Cannot specify both 'value' and 'method'."),
(dict(),
"Must specify a fill 'value' or 'method'."),
(dict(method='bad'),
"Invalid fill method. Expecting .* bad"),
])
def test_fillna_raises(self, fillna_kwargs, msg):
# https://github.com/pandas-dev/pandas/issues/19682
cat = Categorical([1, 2, 3])
with tm.assert_raises_regex(ValueError, msg):
cat.fillna(**fillna_kwargs)
@pytest.mark.parametrize("named", [True, False])
def test_fillna_iterable_category(self, named):
# https://github.com/pandas-dev/pandas/issues/21097
if named:
Point = collections.namedtuple("Point", "x y")
else:
Point = lambda *args: args # tuple
cat = Categorical([Point(0, 0), Point(0, 1), None])
result = cat.fillna(Point(0, 0))
expected = Categorical([Point(0, 0), Point(0, 1), Point(0, 0)])
tm.assert_categorical_equal(result, expected)