projektAI/venv/Lib/site-packages/pandas/tests/base/test_value_counts.py
2021-06-06 22:13:05 +02:00

291 lines
9.3 KiB
Python

import collections
from datetime import timedelta
from io import StringIO
import numpy as np
import pytest
from pandas._libs import iNaT
from pandas.compat.numpy import np_array_datetime64_compat
from pandas.core.dtypes.common import needs_i8_conversion
import pandas as pd
from pandas import (
DatetimeIndex,
Index,
Interval,
IntervalIndex,
Series,
Timedelta,
TimedeltaIndex,
)
import pandas._testing as tm
from pandas.tests.base.common import allow_na_ops
def test_value_counts(index_or_series_obj):
obj = index_or_series_obj
obj = np.repeat(obj, range(1, len(obj) + 1))
result = obj.value_counts()
counter = collections.Counter(obj)
expected = Series(dict(counter.most_common()), dtype=np.int64, name=obj.name)
expected.index = expected.index.astype(obj.dtype)
if isinstance(obj, pd.MultiIndex):
expected.index = Index(expected.index)
# TODO: Order of entries with the same count is inconsistent on CI (gh-32449)
if obj.duplicated().any():
result = result.sort_index()
expected = expected.sort_index()
tm.assert_series_equal(result, expected)
@pytest.mark.parametrize("null_obj", [np.nan, None])
def test_value_counts_null(null_obj, index_or_series_obj):
orig = index_or_series_obj
obj = orig.copy()
if not allow_na_ops(obj):
pytest.skip("type doesn't allow for NA operations")
elif len(obj) < 1:
pytest.skip("Test doesn't make sense on empty data")
elif isinstance(orig, pd.MultiIndex):
pytest.skip(f"MultiIndex can't hold '{null_obj}'")
values = obj.values
if needs_i8_conversion(obj.dtype):
values[0:2] = iNaT
else:
values[0:2] = null_obj
klass = type(obj)
repeated_values = np.repeat(values, range(1, len(values) + 1))
obj = klass(repeated_values, dtype=obj.dtype)
# because np.nan == np.nan is False, but None == None is True
# np.nan would be duplicated, whereas None wouldn't
counter = collections.Counter(obj.dropna())
expected = Series(dict(counter.most_common()), dtype=np.int64)
expected.index = expected.index.astype(obj.dtype)
result = obj.value_counts()
if obj.duplicated().any():
# TODO:
# Order of entries with the same count is inconsistent on CI (gh-32449)
expected = expected.sort_index()
result = result.sort_index()
tm.assert_series_equal(result, expected)
# can't use expected[null_obj] = 3 as
# IntervalIndex doesn't allow assignment
new_entry = Series({np.nan: 3}, dtype=np.int64)
expected = expected.append(new_entry)
result = obj.value_counts(dropna=False)
if obj.duplicated().any():
# TODO:
# Order of entries with the same count is inconsistent on CI (gh-32449)
expected = expected.sort_index()
result = result.sort_index()
tm.assert_series_equal(result, expected)
def test_value_counts_inferred(index_or_series):
klass = index_or_series
s_values = ["a", "b", "b", "b", "b", "c", "d", "d", "a", "a"]
s = klass(s_values)
expected = Series([4, 3, 2, 1], index=["b", "a", "d", "c"])
tm.assert_series_equal(s.value_counts(), expected)
if isinstance(s, Index):
exp = Index(np.unique(np.array(s_values, dtype=np.object_)))
tm.assert_index_equal(s.unique(), exp)
else:
exp = np.unique(np.array(s_values, dtype=np.object_))
tm.assert_numpy_array_equal(s.unique(), exp)
assert s.nunique() == 4
# don't sort, have to sort after the fact as not sorting is
# platform-dep
hist = s.value_counts(sort=False).sort_values()
expected = Series([3, 1, 4, 2], index=list("acbd")).sort_values()
tm.assert_series_equal(hist, expected)
# sort ascending
hist = s.value_counts(ascending=True)
expected = Series([1, 2, 3, 4], index=list("cdab"))
tm.assert_series_equal(hist, expected)
# relative histogram.
hist = s.value_counts(normalize=True)
expected = Series([0.4, 0.3, 0.2, 0.1], index=["b", "a", "d", "c"])
tm.assert_series_equal(hist, expected)
def test_value_counts_bins(index_or_series):
klass = index_or_series
s_values = ["a", "b", "b", "b", "b", "c", "d", "d", "a", "a"]
s = klass(s_values)
# bins
msg = "bins argument only works with numeric data"
with pytest.raises(TypeError, match=msg):
s.value_counts(bins=1)
s1 = Series([1, 1, 2, 3])
res1 = s1.value_counts(bins=1)
exp1 = Series({Interval(0.997, 3.0): 4})
tm.assert_series_equal(res1, exp1)
res1n = s1.value_counts(bins=1, normalize=True)
exp1n = Series({Interval(0.997, 3.0): 1.0})
tm.assert_series_equal(res1n, exp1n)
if isinstance(s1, Index):
tm.assert_index_equal(s1.unique(), Index([1, 2, 3]))
else:
exp = np.array([1, 2, 3], dtype=np.int64)
tm.assert_numpy_array_equal(s1.unique(), exp)
assert s1.nunique() == 3
# these return the same
res4 = s1.value_counts(bins=4, dropna=True)
intervals = IntervalIndex.from_breaks([0.997, 1.5, 2.0, 2.5, 3.0])
exp4 = Series([2, 1, 1, 0], index=intervals.take([0, 1, 3, 2]))
tm.assert_series_equal(res4, exp4)
res4 = s1.value_counts(bins=4, dropna=False)
intervals = IntervalIndex.from_breaks([0.997, 1.5, 2.0, 2.5, 3.0])
exp4 = Series([2, 1, 1, 0], index=intervals.take([0, 1, 3, 2]))
tm.assert_series_equal(res4, exp4)
res4n = s1.value_counts(bins=4, normalize=True)
exp4n = Series([0.5, 0.25, 0.25, 0], index=intervals.take([0, 1, 3, 2]))
tm.assert_series_equal(res4n, exp4n)
# handle NA's properly
s_values = ["a", "b", "b", "b", np.nan, np.nan, "d", "d", "a", "a", "b"]
s = klass(s_values)
expected = Series([4, 3, 2], index=["b", "a", "d"])
tm.assert_series_equal(s.value_counts(), expected)
if isinstance(s, Index):
exp = Index(["a", "b", np.nan, "d"])
tm.assert_index_equal(s.unique(), exp)
else:
exp = np.array(["a", "b", np.nan, "d"], dtype=object)
tm.assert_numpy_array_equal(s.unique(), exp)
assert s.nunique() == 3
s = klass({}) if klass is dict else klass({}, dtype=object)
expected = Series([], dtype=np.int64)
tm.assert_series_equal(s.value_counts(), expected, check_index_type=False)
# returned dtype differs depending on original
if isinstance(s, Index):
tm.assert_index_equal(s.unique(), Index([]), exact=False)
else:
tm.assert_numpy_array_equal(s.unique(), np.array([]), check_dtype=False)
assert s.nunique() == 0
def test_value_counts_datetime64(index_or_series):
klass = index_or_series
# GH 3002, datetime64[ns]
# don't test names though
txt = "\n".join(
[
"xxyyzz20100101PIE",
"xxyyzz20100101GUM",
"xxyyzz20100101EGG",
"xxyyww20090101EGG",
"foofoo20080909PIE",
"foofoo20080909GUM",
]
)
f = StringIO(txt)
df = pd.read_fwf(
f, widths=[6, 8, 3], names=["person_id", "dt", "food"], parse_dates=["dt"]
)
s = klass(df["dt"].copy())
s.name = None
idx = pd.to_datetime(
["2010-01-01 00:00:00", "2008-09-09 00:00:00", "2009-01-01 00:00:00"]
)
expected_s = Series([3, 2, 1], index=idx)
tm.assert_series_equal(s.value_counts(), expected_s)
expected = np_array_datetime64_compat(
["2010-01-01 00:00:00", "2009-01-01 00:00:00", "2008-09-09 00:00:00"],
dtype="datetime64[ns]",
)
if isinstance(s, Index):
tm.assert_index_equal(s.unique(), DatetimeIndex(expected))
else:
tm.assert_numpy_array_equal(s.unique(), expected)
assert s.nunique() == 3
# with NaT
s = df["dt"].copy()
s = klass(list(s.values) + [pd.NaT] * 4)
result = s.value_counts()
assert result.index.dtype == "datetime64[ns]"
tm.assert_series_equal(result, expected_s)
result = s.value_counts(dropna=False)
expected_s = pd.concat([Series([4], index=DatetimeIndex([pd.NaT])), expected_s])
tm.assert_series_equal(result, expected_s)
unique = s.unique()
assert unique.dtype == "datetime64[ns]"
# numpy_array_equal cannot compare pd.NaT
if isinstance(s, Index):
exp_idx = DatetimeIndex(expected.tolist() + [pd.NaT])
tm.assert_index_equal(unique, exp_idx)
else:
tm.assert_numpy_array_equal(unique[:3], expected)
assert pd.isna(unique[3])
assert s.nunique() == 3
assert s.nunique(dropna=False) == 4
# timedelta64[ns]
td = df.dt - df.dt + timedelta(1)
td = klass(td, name="dt")
result = td.value_counts()
expected_s = Series([6], index=[Timedelta("1day")], name="dt")
tm.assert_series_equal(result, expected_s)
expected = TimedeltaIndex(["1 days"], name="dt")
if isinstance(td, Index):
tm.assert_index_equal(td.unique(), expected)
else:
tm.assert_numpy_array_equal(td.unique(), expected.values)
td2 = timedelta(1) + (df.dt - df.dt)
td2 = klass(td2, name="dt")
result2 = td2.value_counts()
tm.assert_series_equal(result2, expected_s)
@pytest.mark.parametrize("dropna", [True, False])
def test_value_counts_with_nan(dropna, index_or_series):
# GH31944
klass = index_or_series
values = [True, pd.NA, np.nan]
s = klass(values)
res = s.value_counts(dropna=dropna)
if dropna is True:
expected = Series([1], index=[True])
else:
expected = Series([2, 1], index=[pd.NA, True])
tm.assert_series_equal(res, expected)