LSR/env/lib/python3.6/site-packages/pandas/tests/groupby/test_counting.py
2020-06-04 17:24:47 +02:00

223 lines
7.5 KiB
Python

from itertools import product
import numpy as np
import pytest
from pandas import DataFrame, MultiIndex, Period, Series, Timedelta, Timestamp
import pandas._testing as tm
class TestCounting:
def test_cumcount(self):
df = DataFrame([["a"], ["a"], ["a"], ["b"], ["a"]], columns=["A"])
g = df.groupby("A")
sg = g.A
expected = Series([0, 1, 2, 0, 3])
tm.assert_series_equal(expected, g.cumcount())
tm.assert_series_equal(expected, sg.cumcount())
def test_cumcount_empty(self):
ge = DataFrame().groupby(level=0)
se = Series(dtype=object).groupby(level=0)
# edge case, as this is usually considered float
e = Series(dtype="int64")
tm.assert_series_equal(e, ge.cumcount())
tm.assert_series_equal(e, se.cumcount())
def test_cumcount_dupe_index(self):
df = DataFrame(
[["a"], ["a"], ["a"], ["b"], ["a"]], columns=["A"], index=[0] * 5
)
g = df.groupby("A")
sg = g.A
expected = Series([0, 1, 2, 0, 3], index=[0] * 5)
tm.assert_series_equal(expected, g.cumcount())
tm.assert_series_equal(expected, sg.cumcount())
def test_cumcount_mi(self):
mi = MultiIndex.from_tuples([[0, 1], [1, 2], [2, 2], [2, 2], [1, 0]])
df = DataFrame([["a"], ["a"], ["a"], ["b"], ["a"]], columns=["A"], index=mi)
g = df.groupby("A")
sg = g.A
expected = Series([0, 1, 2, 0, 3], index=mi)
tm.assert_series_equal(expected, g.cumcount())
tm.assert_series_equal(expected, sg.cumcount())
def test_cumcount_groupby_not_col(self):
df = DataFrame(
[["a"], ["a"], ["a"], ["b"], ["a"]], columns=["A"], index=[0] * 5
)
g = df.groupby([0, 0, 0, 1, 0])
sg = g.A
expected = Series([0, 1, 2, 0, 3], index=[0] * 5)
tm.assert_series_equal(expected, g.cumcount())
tm.assert_series_equal(expected, sg.cumcount())
def test_ngroup(self):
df = DataFrame({"A": list("aaaba")})
g = df.groupby("A")
sg = g.A
expected = Series([0, 0, 0, 1, 0])
tm.assert_series_equal(expected, g.ngroup())
tm.assert_series_equal(expected, sg.ngroup())
def test_ngroup_distinct(self):
df = DataFrame({"A": list("abcde")})
g = df.groupby("A")
sg = g.A
expected = Series(range(5), dtype="int64")
tm.assert_series_equal(expected, g.ngroup())
tm.assert_series_equal(expected, sg.ngroup())
def test_ngroup_one_group(self):
df = DataFrame({"A": [0] * 5})
g = df.groupby("A")
sg = g.A
expected = Series([0] * 5)
tm.assert_series_equal(expected, g.ngroup())
tm.assert_series_equal(expected, sg.ngroup())
def test_ngroup_empty(self):
ge = DataFrame().groupby(level=0)
se = Series(dtype=object).groupby(level=0)
# edge case, as this is usually considered float
e = Series(dtype="int64")
tm.assert_series_equal(e, ge.ngroup())
tm.assert_series_equal(e, se.ngroup())
def test_ngroup_series_matches_frame(self):
df = DataFrame({"A": list("aaaba")})
s = Series(list("aaaba"))
tm.assert_series_equal(df.groupby(s).ngroup(), s.groupby(s).ngroup())
def test_ngroup_dupe_index(self):
df = DataFrame({"A": list("aaaba")}, index=[0] * 5)
g = df.groupby("A")
sg = g.A
expected = Series([0, 0, 0, 1, 0], index=[0] * 5)
tm.assert_series_equal(expected, g.ngroup())
tm.assert_series_equal(expected, sg.ngroup())
def test_ngroup_mi(self):
mi = MultiIndex.from_tuples([[0, 1], [1, 2], [2, 2], [2, 2], [1, 0]])
df = DataFrame({"A": list("aaaba")}, index=mi)
g = df.groupby("A")
sg = g.A
expected = Series([0, 0, 0, 1, 0], index=mi)
tm.assert_series_equal(expected, g.ngroup())
tm.assert_series_equal(expected, sg.ngroup())
def test_ngroup_groupby_not_col(self):
df = DataFrame({"A": list("aaaba")}, index=[0] * 5)
g = df.groupby([0, 0, 0, 1, 0])
sg = g.A
expected = Series([0, 0, 0, 1, 0], index=[0] * 5)
tm.assert_series_equal(expected, g.ngroup())
tm.assert_series_equal(expected, sg.ngroup())
def test_ngroup_descending(self):
df = DataFrame(["a", "a", "b", "a", "b"], columns=["A"])
g = df.groupby(["A"])
ascending = Series([0, 0, 1, 0, 1])
descending = Series([1, 1, 0, 1, 0])
tm.assert_series_equal(descending, (g.ngroups - 1) - ascending)
tm.assert_series_equal(ascending, g.ngroup(ascending=True))
tm.assert_series_equal(descending, g.ngroup(ascending=False))
def test_ngroup_matches_cumcount(self):
# verify one manually-worked out case works
df = DataFrame(
[["a", "x"], ["a", "y"], ["b", "x"], ["a", "x"], ["b", "y"]],
columns=["A", "X"],
)
g = df.groupby(["A", "X"])
g_ngroup = g.ngroup()
g_cumcount = g.cumcount()
expected_ngroup = Series([0, 1, 2, 0, 3])
expected_cumcount = Series([0, 0, 0, 1, 0])
tm.assert_series_equal(g_ngroup, expected_ngroup)
tm.assert_series_equal(g_cumcount, expected_cumcount)
def test_ngroup_cumcount_pair(self):
# brute force comparison for all small series
for p in product(range(3), repeat=4):
df = DataFrame({"a": p})
g = df.groupby(["a"])
order = sorted(set(p))
ngroupd = [order.index(val) for val in p]
cumcounted = [p[:i].count(val) for i, val in enumerate(p)]
tm.assert_series_equal(g.ngroup(), Series(ngroupd))
tm.assert_series_equal(g.cumcount(), Series(cumcounted))
def test_ngroup_respects_groupby_order(self):
np.random.seed(0)
df = DataFrame({"a": np.random.choice(list("abcdef"), 100)})
for sort_flag in (False, True):
g = df.groupby(["a"], sort=sort_flag)
df["group_id"] = -1
df["group_index"] = -1
for i, (_, group) in enumerate(g):
df.loc[group.index, "group_id"] = i
for j, ind in enumerate(group.index):
df.loc[ind, "group_index"] = j
tm.assert_series_equal(Series(df["group_id"].values), g.ngroup())
tm.assert_series_equal(Series(df["group_index"].values), g.cumcount())
@pytest.mark.parametrize(
"datetimelike",
[
[Timestamp(f"2016-05-{i:02d} 20:09:25+00:00") for i in range(1, 4)],
[Timestamp(f"2016-05-{i:02d} 20:09:25") for i in range(1, 4)],
[Timedelta(x, unit="h") for x in range(1, 4)],
[Period(freq="2W", year=2017, month=x) for x in range(1, 4)],
],
)
def test_count_with_datetimelike(self, datetimelike):
# test for #13393, where DataframeGroupBy.count() fails
# when counting a datetimelike column.
df = DataFrame({"x": ["a", "a", "b"], "y": datetimelike})
res = df.groupby("x").count()
expected = DataFrame({"y": [2, 1]}, index=["a", "b"])
expected.index.name = "x"
tm.assert_frame_equal(expected, res)
def test_count_with_only_nans_in_first_group(self):
# GH21956
df = DataFrame({"A": [np.nan, np.nan], "B": ["a", "b"], "C": [1, 2]})
result = df.groupby(["A", "B"]).C.count()
mi = MultiIndex(levels=[[], ["a", "b"]], codes=[[], []], names=["A", "B"])
expected = Series([], index=mi, dtype=np.int64, name="C")
tm.assert_series_equal(result, expected, check_index_type=False)