aoc-2022/venv/Lib/site-packages/pandas/tests/groupby/test_grouping.py

1027 lines
36 KiB
Python

""" test where we are determining what we are grouping, or getting groups """
import numpy as np
import pytest
import pandas as pd
from pandas import (
CategoricalIndex,
DataFrame,
Index,
MultiIndex,
Series,
Timestamp,
date_range,
)
import pandas._testing as tm
from pandas.core.api import (
Float64Index,
Int64Index,
)
from pandas.core.groupby.grouper import Grouping
# selection
# --------------------------------
class TestSelection:
def test_select_bad_cols(self):
df = DataFrame([[1, 2]], columns=["A", "B"])
g = df.groupby("A")
with pytest.raises(KeyError, match="\"Columns not found: 'C'\""):
g[["C"]]
with pytest.raises(KeyError, match="^[^A]+$"):
# A should not be referenced as a bad column...
# will have to rethink regex if you change message!
g[["A", "C"]]
def test_groupby_duplicated_column_errormsg(self):
# GH7511
df = DataFrame(
columns=["A", "B", "A", "C"], data=[range(4), range(2, 6), range(0, 8, 2)]
)
msg = "Grouper for 'A' not 1-dimensional"
with pytest.raises(ValueError, match=msg):
df.groupby("A")
with pytest.raises(ValueError, match=msg):
df.groupby(["A", "B"])
grouped = df.groupby("B")
c = grouped.count()
assert c.columns.nlevels == 1
assert c.columns.size == 3
def test_column_select_via_attr(self, df):
result = df.groupby("A").C.sum()
expected = df.groupby("A")["C"].sum()
tm.assert_series_equal(result, expected)
df["mean"] = 1.5
msg = "The default value of numeric_only"
with tm.assert_produces_warning(FutureWarning, match=msg):
result = df.groupby("A").mean()
expected = df.groupby("A").agg(np.mean)
tm.assert_frame_equal(result, expected)
def test_getitem_list_of_columns(self):
df = DataFrame(
{
"A": ["foo", "bar", "foo", "bar", "foo", "bar", "foo", "foo"],
"B": ["one", "one", "two", "three", "two", "two", "one", "three"],
"C": np.random.randn(8),
"D": np.random.randn(8),
"E": np.random.randn(8),
}
)
result = df.groupby("A")[["C", "D"]].mean()
result2 = df.groupby("A")[df.columns[2:4]].mean()
expected = df.loc[:, ["A", "C", "D"]].groupby("A").mean()
tm.assert_frame_equal(result, expected)
tm.assert_frame_equal(result2, expected)
def test_getitem_numeric_column_names(self):
# GH #13731
df = DataFrame(
{
0: list("abcd") * 2,
2: np.random.randn(8),
4: np.random.randn(8),
6: np.random.randn(8),
}
)
result = df.groupby(0)[df.columns[1:3]].mean()
result2 = df.groupby(0)[[2, 4]].mean()
expected = df.loc[:, [0, 2, 4]].groupby(0).mean()
tm.assert_frame_equal(result, expected)
tm.assert_frame_equal(result2, expected)
# per GH 23566 this should raise a FutureWarning
with tm.assert_produces_warning(FutureWarning):
df.groupby(0)[2, 4].mean()
def test_getitem_single_list_of_columns(self, df):
# per GH 23566 this should raise a FutureWarning
with tm.assert_produces_warning(FutureWarning):
df.groupby("A")["C", "D"].mean()
def test_getitem_single_column(self):
df = DataFrame(
{
"A": ["foo", "bar", "foo", "bar", "foo", "bar", "foo", "foo"],
"B": ["one", "one", "two", "three", "two", "two", "one", "three"],
"C": np.random.randn(8),
"D": np.random.randn(8),
"E": np.random.randn(8),
}
)
result = df.groupby("A")["C"].mean()
as_frame = df.loc[:, ["A", "C"]].groupby("A").mean()
as_series = as_frame.iloc[:, 0]
expected = as_series
tm.assert_series_equal(result, expected)
def test_indices_grouped_by_tuple_with_lambda(self):
# GH 36158
df = DataFrame(
{"Tuples": ((x, y) for x in [0, 1] for y in np.random.randint(3, 5, 5))}
)
gb = df.groupby("Tuples")
gb_lambda = df.groupby(lambda x: df.iloc[x, 0])
expected = gb.indices
result = gb_lambda.indices
tm.assert_dict_equal(result, expected)
# grouping
# --------------------------------
class TestGrouping:
@pytest.mark.parametrize(
"index",
[
tm.makeFloatIndex,
tm.makeStringIndex,
tm.makeIntIndex,
tm.makeDateIndex,
tm.makePeriodIndex,
],
)
def test_grouper_index_types(self, index):
# related GH5375
# groupby misbehaving when using a Floatlike index
df = DataFrame(np.arange(10).reshape(5, 2), columns=list("AB"))
df.index = index(len(df))
df.groupby(list("abcde"), group_keys=False).apply(lambda x: x)
df.index = list(reversed(df.index.tolist()))
df.groupby(list("abcde"), group_keys=False).apply(lambda x: x)
def test_grouper_multilevel_freq(self):
# GH 7885
# with level and freq specified in a pd.Grouper
from datetime import (
date,
timedelta,
)
d0 = date.today() - timedelta(days=14)
dates = date_range(d0, date.today())
date_index = MultiIndex.from_product([dates, dates], names=["foo", "bar"])
df = DataFrame(np.random.randint(0, 100, 225), index=date_index)
# Check string level
expected = (
df.reset_index()
.groupby([pd.Grouper(key="foo", freq="W"), pd.Grouper(key="bar", freq="W")])
.sum()
)
# reset index changes columns dtype to object
expected.columns = Index([0], dtype="int64")
result = df.groupby(
[pd.Grouper(level="foo", freq="W"), pd.Grouper(level="bar", freq="W")]
).sum()
tm.assert_frame_equal(result, expected)
# Check integer level
result = df.groupby(
[pd.Grouper(level=0, freq="W"), pd.Grouper(level=1, freq="W")]
).sum()
tm.assert_frame_equal(result, expected)
def test_grouper_creation_bug(self):
# GH 8795
df = DataFrame({"A": [0, 0, 1, 1, 2, 2], "B": [1, 2, 3, 4, 5, 6]})
g = df.groupby("A")
expected = g.sum()
g = df.groupby(pd.Grouper(key="A"))
result = g.sum()
tm.assert_frame_equal(result, expected)
g = df.groupby(pd.Grouper(key="A", axis=0))
result = g.sum()
tm.assert_frame_equal(result, expected)
result = g.apply(lambda x: x.sum())
expected["A"] = [0, 2, 4]
expected = expected.loc[:, ["A", "B"]]
tm.assert_frame_equal(result, expected)
# GH14334
# pd.Grouper(key=...) may be passed in a list
df = DataFrame(
{"A": [0, 0, 0, 1, 1, 1], "B": [1, 1, 2, 2, 3, 3], "C": [1, 2, 3, 4, 5, 6]}
)
# Group by single column
expected = df.groupby("A").sum()
g = df.groupby([pd.Grouper(key="A")])
result = g.sum()
tm.assert_frame_equal(result, expected)
# Group by two columns
# using a combination of strings and Grouper objects
expected = df.groupby(["A", "B"]).sum()
# Group with two Grouper objects
g = df.groupby([pd.Grouper(key="A"), pd.Grouper(key="B")])
result = g.sum()
tm.assert_frame_equal(result, expected)
# Group with a string and a Grouper object
g = df.groupby(["A", pd.Grouper(key="B")])
result = g.sum()
tm.assert_frame_equal(result, expected)
# Group with a Grouper object and a string
g = df.groupby([pd.Grouper(key="A"), "B"])
result = g.sum()
tm.assert_frame_equal(result, expected)
# GH8866
s = Series(
np.arange(8, dtype="int64"),
index=MultiIndex.from_product(
[list("ab"), range(2), date_range("20130101", periods=2)],
names=["one", "two", "three"],
),
)
result = s.groupby(pd.Grouper(level="three", freq="M")).sum()
expected = Series(
[28],
index=pd.DatetimeIndex([Timestamp("2013-01-31")], freq="M", name="three"),
)
tm.assert_series_equal(result, expected)
# just specifying a level breaks
result = s.groupby(pd.Grouper(level="one")).sum()
expected = s.groupby(level="one").sum()
tm.assert_series_equal(result, expected)
def test_grouper_column_and_index(self):
# GH 14327
# Grouping a multi-index frame by a column and an index level should
# be equivalent to resetting the index and grouping by two columns
idx = MultiIndex.from_tuples(
[("a", 1), ("a", 2), ("a", 3), ("b", 1), ("b", 2), ("b", 3)]
)
idx.names = ["outer", "inner"]
df_multi = DataFrame(
{"A": np.arange(6), "B": ["one", "one", "two", "two", "one", "one"]},
index=idx,
)
msg = "The default value of numeric_only"
with tm.assert_produces_warning(FutureWarning, match=msg):
result = df_multi.groupby(["B", pd.Grouper(level="inner")]).mean()
expected = df_multi.reset_index().groupby(["B", "inner"]).mean()
tm.assert_frame_equal(result, expected)
# Test the reverse grouping order
with tm.assert_produces_warning(FutureWarning, match=msg):
result = df_multi.groupby([pd.Grouper(level="inner"), "B"]).mean()
expected = df_multi.reset_index().groupby(["inner", "B"]).mean()
tm.assert_frame_equal(result, expected)
# Grouping a single-index frame by a column and the index should
# be equivalent to resetting the index and grouping by two columns
df_single = df_multi.reset_index("outer")
with tm.assert_produces_warning(FutureWarning, match=msg):
result = df_single.groupby(["B", pd.Grouper(level="inner")]).mean()
expected = df_single.reset_index().groupby(["B", "inner"]).mean()
tm.assert_frame_equal(result, expected)
# Test the reverse grouping order
with tm.assert_produces_warning(FutureWarning, match=msg):
result = df_single.groupby([pd.Grouper(level="inner"), "B"]).mean()
expected = df_single.reset_index().groupby(["inner", "B"]).mean()
tm.assert_frame_equal(result, expected)
def test_groupby_levels_and_columns(self):
# GH9344, GH9049
idx_names = ["x", "y"]
idx = MultiIndex.from_tuples([(1, 1), (1, 2), (3, 4), (5, 6)], names=idx_names)
df = DataFrame(np.arange(12).reshape(-1, 3), index=idx)
by_levels = df.groupby(level=idx_names).mean()
# reset_index changes columns dtype to object
by_columns = df.reset_index().groupby(idx_names).mean()
# without casting, by_columns.columns is object-dtype
by_columns.columns = by_columns.columns.astype(np.int64)
tm.assert_frame_equal(by_levels, by_columns)
def test_groupby_categorical_index_and_columns(self, observed):
# GH18432, adapted for GH25871
columns = ["A", "B", "A", "B"]
categories = ["B", "A"]
data = np.array(
[[1, 2, 1, 2], [1, 2, 1, 2], [1, 2, 1, 2], [1, 2, 1, 2], [1, 2, 1, 2]], int
)
cat_columns = CategoricalIndex(columns, categories=categories, ordered=True)
df = DataFrame(data=data, columns=cat_columns)
result = df.groupby(axis=1, level=0, observed=observed).sum()
expected_data = np.array([[4, 2], [4, 2], [4, 2], [4, 2], [4, 2]], int)
expected_columns = CategoricalIndex(
categories, categories=categories, ordered=True
)
expected = DataFrame(data=expected_data, columns=expected_columns)
tm.assert_frame_equal(result, expected)
# test transposed version
df = DataFrame(data.T, index=cat_columns)
result = df.groupby(axis=0, level=0, observed=observed).sum()
expected = DataFrame(data=expected_data.T, index=expected_columns)
tm.assert_frame_equal(result, expected)
def test_grouper_getting_correct_binner(self):
# GH 10063
# using a non-time-based grouper and a time-based grouper
# and specifying levels
df = DataFrame(
{"A": 1},
index=MultiIndex.from_product(
[list("ab"), date_range("20130101", periods=80)], names=["one", "two"]
),
)
result = df.groupby(
[pd.Grouper(level="one"), pd.Grouper(level="two", freq="M")]
).sum()
expected = DataFrame(
{"A": [31, 28, 21, 31, 28, 21]},
index=MultiIndex.from_product(
[list("ab"), date_range("20130101", freq="M", periods=3)],
names=["one", "two"],
),
)
tm.assert_frame_equal(result, expected)
def test_grouper_iter(self, df):
assert sorted(df.groupby("A").grouper) == ["bar", "foo"]
def test_empty_groups(self, df):
# see gh-1048
with pytest.raises(ValueError, match="No group keys passed!"):
df.groupby([])
def test_groupby_grouper(self, df):
grouped = df.groupby("A")
msg = "The default value of numeric_only"
with tm.assert_produces_warning(FutureWarning, match=msg):
result = df.groupby(grouped.grouper).mean()
expected = grouped.mean()
tm.assert_frame_equal(result, expected)
def test_groupby_dict_mapping(self):
# GH #679
from pandas import Series
s = Series({"T1": 5})
result = s.groupby({"T1": "T2"}).agg(sum)
expected = s.groupby(["T2"]).agg(sum)
tm.assert_series_equal(result, expected)
s = Series([1.0, 2.0, 3.0, 4.0], index=list("abcd"))
mapping = {"a": 0, "b": 0, "c": 1, "d": 1}
result = s.groupby(mapping).mean()
result2 = s.groupby(mapping).agg(np.mean)
expected = s.groupby([0, 0, 1, 1]).mean()
expected2 = s.groupby([0, 0, 1, 1]).mean()
tm.assert_series_equal(result, expected)
tm.assert_series_equal(result, result2)
tm.assert_series_equal(result, expected2)
@pytest.mark.parametrize(
"index",
[
[0, 1, 2, 3],
["a", "b", "c", "d"],
[Timestamp(2021, 7, 28 + i) for i in range(4)],
],
)
def test_groupby_series_named_with_tuple(self, frame_or_series, index):
# GH 42731
obj = frame_or_series([1, 2, 3, 4], index=index)
groups = Series([1, 0, 1, 0], index=index, name=("a", "a"))
result = obj.groupby(groups).last()
expected = frame_or_series([4, 3])
expected.index.name = ("a", "a")
tm.assert_equal(result, expected)
def test_groupby_grouper_f_sanity_checked(self):
dates = date_range("01-Jan-2013", periods=12, freq="MS")
ts = Series(np.random.randn(12), index=dates)
# GH3035
# index.map is used to apply grouper to the index
# if it fails on the elements, map tries it on the entire index as
# a sequence. That can yield invalid results that cause trouble
# down the line.
# the surprise comes from using key[0:6] rather than str(key)[0:6]
# when the elements are Timestamp.
# the result is Index[0:6], very confusing.
msg = r"Grouper result violates len\(labels\) == len\(data\)"
with pytest.raises(AssertionError, match=msg):
ts.groupby(lambda key: key[0:6])
def test_grouping_error_on_multidim_input(self, df):
msg = "Grouper for '<class 'pandas.core.frame.DataFrame'>' not 1-dimensional"
with pytest.raises(ValueError, match=msg):
Grouping(df.index, df[["A", "A"]])
def test_multiindex_passthru(self):
# GH 7997
# regression from 0.14.1
df = DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
df.columns = MultiIndex.from_tuples([(0, 1), (1, 1), (2, 1)])
result = df.groupby(axis=1, level=[0, 1]).first()
tm.assert_frame_equal(result, df)
def test_multiindex_negative_level(self, mframe):
# GH 13901
result = mframe.groupby(level=-1).sum()
expected = mframe.groupby(level="second").sum()
tm.assert_frame_equal(result, expected)
result = mframe.groupby(level=-2).sum()
expected = mframe.groupby(level="first").sum()
tm.assert_frame_equal(result, expected)
result = mframe.groupby(level=[-2, -1]).sum()
expected = mframe.sort_index()
tm.assert_frame_equal(result, expected)
result = mframe.groupby(level=[-1, "first"]).sum()
expected = mframe.groupby(level=["second", "first"]).sum()
tm.assert_frame_equal(result, expected)
def test_multifunc_select_col_integer_cols(self, df):
df.columns = np.arange(len(df.columns))
# it works!
df.groupby(1, as_index=False)[2].agg({"Q": np.mean})
def test_multiindex_columns_empty_level(self):
lst = [["count", "values"], ["to filter", ""]]
midx = MultiIndex.from_tuples(lst)
df = DataFrame([[1, "A"]], columns=midx)
grouped = df.groupby("to filter").groups
assert grouped["A"] == [0]
grouped = df.groupby([("to filter", "")]).groups
assert grouped["A"] == [0]
df = DataFrame([[1, "A"], [2, "B"]], columns=midx)
expected = df.groupby("to filter").groups
result = df.groupby([("to filter", "")]).groups
assert result == expected
df = DataFrame([[1, "A"], [2, "A"]], columns=midx)
expected = df.groupby("to filter").groups
result = df.groupby([("to filter", "")]).groups
tm.assert_dict_equal(result, expected)
def test_groupby_multiindex_tuple(self):
# GH 17979
df = DataFrame(
[[1, 2, 3, 4], [3, 4, 5, 6], [1, 4, 2, 3]],
columns=MultiIndex.from_arrays([["a", "b", "b", "c"], [1, 1, 2, 2]]),
)
expected = df.groupby([("b", 1)]).groups
result = df.groupby(("b", 1)).groups
tm.assert_dict_equal(expected, result)
df2 = DataFrame(
df.values,
columns=MultiIndex.from_arrays(
[["a", "b", "b", "c"], ["d", "d", "e", "e"]]
),
)
expected = df2.groupby([("b", "d")]).groups
result = df.groupby(("b", 1)).groups
tm.assert_dict_equal(expected, result)
df3 = DataFrame(df.values, columns=[("a", "d"), ("b", "d"), ("b", "e"), "c"])
expected = df3.groupby([("b", "d")]).groups
result = df.groupby(("b", 1)).groups
tm.assert_dict_equal(expected, result)
@pytest.mark.parametrize("sort", [True, False])
def test_groupby_level(self, sort, mframe, df):
# GH 17537
frame = mframe
deleveled = frame.reset_index()
result0 = frame.groupby(level=0, sort=sort).sum()
result1 = frame.groupby(level=1, sort=sort).sum()
expected0 = frame.groupby(deleveled["first"].values, sort=sort).sum()
expected1 = frame.groupby(deleveled["second"].values, sort=sort).sum()
expected0.index.name = "first"
expected1.index.name = "second"
assert result0.index.name == "first"
assert result1.index.name == "second"
tm.assert_frame_equal(result0, expected0)
tm.assert_frame_equal(result1, expected1)
assert result0.index.name == frame.index.names[0]
assert result1.index.name == frame.index.names[1]
# groupby level name
result0 = frame.groupby(level="first", sort=sort).sum()
result1 = frame.groupby(level="second", sort=sort).sum()
tm.assert_frame_equal(result0, expected0)
tm.assert_frame_equal(result1, expected1)
# axis=1
result0 = frame.T.groupby(level=0, axis=1, sort=sort).sum()
result1 = frame.T.groupby(level=1, axis=1, sort=sort).sum()
tm.assert_frame_equal(result0, expected0.T)
tm.assert_frame_equal(result1, expected1.T)
# raise exception for non-MultiIndex
msg = "level > 0 or level < -1 only valid with MultiIndex"
with pytest.raises(ValueError, match=msg):
df.groupby(level=1)
def test_groupby_level_index_names(self, axis):
# GH4014 this used to raise ValueError since 'exp'>1 (in py2)
df = DataFrame({"exp": ["A"] * 3 + ["B"] * 3, "var1": range(6)}).set_index(
"exp"
)
if axis in (1, "columns"):
df = df.T
df.groupby(level="exp", axis=axis)
msg = f"level name foo is not the name of the {df._get_axis_name(axis)}"
with pytest.raises(ValueError, match=msg):
df.groupby(level="foo", axis=axis)
@pytest.mark.parametrize("sort", [True, False])
def test_groupby_level_with_nas(self, sort):
# GH 17537
index = MultiIndex(
levels=[[1, 0], [0, 1, 2, 3]],
codes=[[1, 1, 1, 1, 0, 0, 0, 0], [0, 1, 2, 3, 0, 1, 2, 3]],
)
# factorizing doesn't confuse things
s = Series(np.arange(8.0), index=index)
result = s.groupby(level=0, sort=sort).sum()
expected = Series([6.0, 22.0], index=[0, 1])
tm.assert_series_equal(result, expected)
index = MultiIndex(
levels=[[1, 0], [0, 1, 2, 3]],
codes=[[1, 1, 1, 1, -1, 0, 0, 0], [0, 1, 2, 3, 0, 1, 2, 3]],
)
# factorizing doesn't confuse things
s = Series(np.arange(8.0), index=index)
result = s.groupby(level=0, sort=sort).sum()
expected = Series([6.0, 18.0], index=[0.0, 1.0])
tm.assert_series_equal(result, expected)
def test_groupby_args(self, mframe):
# PR8618 and issue 8015
frame = mframe
msg = "You have to supply one of 'by' and 'level'"
with pytest.raises(TypeError, match=msg):
frame.groupby()
msg = "You have to supply one of 'by' and 'level'"
with pytest.raises(TypeError, match=msg):
frame.groupby(by=None, level=None)
@pytest.mark.parametrize(
"sort,labels",
[
[True, [2, 2, 2, 0, 0, 1, 1, 3, 3, 3]],
[False, [0, 0, 0, 1, 1, 2, 2, 3, 3, 3]],
],
)
def test_level_preserve_order(self, sort, labels, mframe):
# GH 17537
grouped = mframe.groupby(level=0, sort=sort)
exp_labels = np.array(labels, np.intp)
tm.assert_almost_equal(grouped.grouper.codes[0], exp_labels)
def test_grouping_labels(self, mframe):
grouped = mframe.groupby(mframe.index.get_level_values(0))
exp_labels = np.array([2, 2, 2, 0, 0, 1, 1, 3, 3, 3], dtype=np.intp)
tm.assert_almost_equal(grouped.grouper.codes[0], exp_labels)
def test_list_grouper_with_nat(self):
# GH 14715
df = DataFrame({"date": date_range("1/1/2011", periods=365, freq="D")})
df.iloc[-1] = pd.NaT
grouper = pd.Grouper(key="date", freq="AS")
# Grouper in a list grouping
result = df.groupby([grouper])
expected = {Timestamp("2011-01-01"): Index(list(range(364)))}
tm.assert_dict_equal(result.groups, expected)
# Test case without a list
result = df.groupby(grouper)
expected = {Timestamp("2011-01-01"): 365}
tm.assert_dict_equal(result.groups, expected)
@pytest.mark.parametrize(
"func,expected",
[
(
"transform",
Series(name=2, dtype=np.float64, index=Index([])),
),
(
"agg",
Series(name=2, dtype=np.float64, index=Float64Index([], name=1)),
),
(
"apply",
Series(name=2, dtype=np.float64, index=Float64Index([], name=1)),
),
],
)
def test_evaluate_with_empty_groups(self, func, expected):
# 26208
# test transform'ing empty groups
# (not testing other agg fns, because they return
# different index objects.
df = DataFrame({1: [], 2: []})
g = df.groupby(1, group_keys=False)
result = getattr(g[2], func)(lambda x: x)
tm.assert_series_equal(result, expected)
def test_groupby_empty(self):
# https://github.com/pandas-dev/pandas/issues/27190
s = Series([], name="name", dtype="float64")
gr = s.groupby([])
result = gr.mean()
tm.assert_series_equal(result, s)
# check group properties
assert len(gr.grouper.groupings) == 1
tm.assert_numpy_array_equal(
gr.grouper.group_info[0], np.array([], dtype=np.dtype(np.intp))
)
tm.assert_numpy_array_equal(
gr.grouper.group_info[1], np.array([], dtype=np.dtype(np.intp))
)
assert gr.grouper.group_info[2] == 0
# check name
assert s.groupby(s).grouper.names == ["name"]
def test_groupby_level_index_value_all_na(self):
# issue 20519
df = DataFrame(
[["x", np.nan, 10], [None, np.nan, 20]], columns=["A", "B", "C"]
).set_index(["A", "B"])
result = df.groupby(level=["A", "B"]).sum()
expected = DataFrame(
data=[],
index=MultiIndex(
levels=[Index(["x"], dtype="object"), Index([], dtype="float64")],
codes=[[], []],
names=["A", "B"],
),
columns=["C"],
dtype="int64",
)
tm.assert_frame_equal(result, expected)
def test_groupby_multiindex_level_empty(self):
# https://github.com/pandas-dev/pandas/issues/31670
df = DataFrame(
[[123, "a", 1.0], [123, "b", 2.0]], columns=["id", "category", "value"]
)
df = df.set_index(["id", "category"])
empty = df[df.value < 0]
result = empty.groupby("id").sum()
expected = DataFrame(
dtype="float64", columns=["value"], index=Int64Index([], name="id")
)
tm.assert_frame_equal(result, expected)
# get_group
# --------------------------------
class TestGetGroup:
def test_get_group(self):
# GH 5267
# be datelike friendly
df = DataFrame(
{
"DATE": pd.to_datetime(
[
"10-Oct-2013",
"10-Oct-2013",
"10-Oct-2013",
"11-Oct-2013",
"11-Oct-2013",
"11-Oct-2013",
]
),
"label": ["foo", "foo", "bar", "foo", "foo", "bar"],
"VAL": [1, 2, 3, 4, 5, 6],
}
)
g = df.groupby("DATE")
key = list(g.groups)[0]
result1 = g.get_group(key)
result2 = g.get_group(Timestamp(key).to_pydatetime())
result3 = g.get_group(str(Timestamp(key)))
tm.assert_frame_equal(result1, result2)
tm.assert_frame_equal(result1, result3)
g = df.groupby(["DATE", "label"])
key = list(g.groups)[0]
result1 = g.get_group(key)
result2 = g.get_group((Timestamp(key[0]).to_pydatetime(), key[1]))
result3 = g.get_group((str(Timestamp(key[0])), key[1]))
tm.assert_frame_equal(result1, result2)
tm.assert_frame_equal(result1, result3)
# must pass a same-length tuple with multiple keys
msg = "must supply a tuple to get_group with multiple grouping keys"
with pytest.raises(ValueError, match=msg):
g.get_group("foo")
with pytest.raises(ValueError, match=msg):
g.get_group("foo")
msg = "must supply a same-length tuple to get_group with multiple grouping keys"
with pytest.raises(ValueError, match=msg):
g.get_group(("foo", "bar", "baz"))
def test_get_group_empty_bins(self, observed):
d = DataFrame([3, 1, 7, 6])
bins = [0, 5, 10, 15]
g = d.groupby(pd.cut(d[0], bins), observed=observed)
# TODO: should prob allow a str of Interval work as well
# IOW '(0, 5]'
result = g.get_group(pd.Interval(0, 5))
expected = DataFrame([3, 1], index=[0, 1])
tm.assert_frame_equal(result, expected)
msg = r"Interval\(10, 15, closed='right'\)"
with pytest.raises(KeyError, match=msg):
g.get_group(pd.Interval(10, 15))
def test_get_group_grouped_by_tuple(self):
# GH 8121
df = DataFrame([[(1,), (1, 2), (1,), (1, 2)]], index=["ids"]).T
gr = df.groupby("ids")
expected = DataFrame({"ids": [(1,), (1,)]}, index=[0, 2])
result = gr.get_group((1,))
tm.assert_frame_equal(result, expected)
dt = pd.to_datetime(["2010-01-01", "2010-01-02", "2010-01-01", "2010-01-02"])
df = DataFrame({"ids": [(x,) for x in dt]})
gr = df.groupby("ids")
result = gr.get_group(("2010-01-01",))
expected = DataFrame({"ids": [(dt[0],), (dt[0],)]}, index=[0, 2])
tm.assert_frame_equal(result, expected)
def test_get_group_grouped_by_tuple_with_lambda(self):
# GH 36158
df = DataFrame(
{"Tuples": ((x, y) for x in [0, 1] for y in np.random.randint(3, 5, 5))}
)
gb = df.groupby("Tuples")
gb_lambda = df.groupby(lambda x: df.iloc[x, 0])
expected = gb.get_group(list(gb.groups.keys())[0])
result = gb_lambda.get_group(list(gb_lambda.groups.keys())[0])
tm.assert_frame_equal(result, expected)
def test_groupby_with_empty(self):
index = pd.DatetimeIndex(())
data = ()
series = Series(data, index, dtype=object)
grouper = pd.Grouper(freq="D")
grouped = series.groupby(grouper)
assert next(iter(grouped), None) is None
def test_groupby_with_single_column(self):
df = DataFrame({"a": list("abssbab")})
tm.assert_frame_equal(df.groupby("a").get_group("a"), df.iloc[[0, 5]])
# GH 13530
exp = DataFrame(index=Index(["a", "b", "s"], name="a"))
tm.assert_frame_equal(df.groupby("a").count(), exp)
tm.assert_frame_equal(df.groupby("a").sum(), exp)
tm.assert_frame_equal(df.groupby("a").nth(1), exp)
def test_gb_key_len_equal_axis_len(self):
# GH16843
# test ensures that index and column keys are recognized correctly
# when number of keys equals axis length of groupby
df = DataFrame(
[["foo", "bar", "B", 1], ["foo", "bar", "B", 2], ["foo", "baz", "C", 3]],
columns=["first", "second", "third", "one"],
)
df = df.set_index(["first", "second"])
df = df.groupby(["first", "second", "third"]).size()
assert df.loc[("foo", "bar", "B")] == 2
assert df.loc[("foo", "baz", "C")] == 1
# groups & iteration
# --------------------------------
class TestIteration:
def test_groups(self, df):
grouped = df.groupby(["A"])
groups = grouped.groups
assert groups is grouped.groups # caching works
for k, v in grouped.groups.items():
assert (df.loc[v]["A"] == k).all()
grouped = df.groupby(["A", "B"])
groups = grouped.groups
assert groups is grouped.groups # caching works
for k, v in grouped.groups.items():
assert (df.loc[v]["A"] == k[0]).all()
assert (df.loc[v]["B"] == k[1]).all()
def test_grouping_is_iterable(self, tsframe):
# this code path isn't used anywhere else
# not sure it's useful
grouped = tsframe.groupby([lambda x: x.weekday(), lambda x: x.year])
# test it works
for g in grouped.grouper.groupings[0]:
pass
def test_multi_iter(self):
s = Series(np.arange(6))
k1 = np.array(["a", "a", "a", "b", "b", "b"])
k2 = np.array(["1", "2", "1", "2", "1", "2"])
grouped = s.groupby([k1, k2])
iterated = list(grouped)
expected = [
("a", "1", s[[0, 2]]),
("a", "2", s[[1]]),
("b", "1", s[[4]]),
("b", "2", s[[3, 5]]),
]
for i, ((one, two), three) in enumerate(iterated):
e1, e2, e3 = expected[i]
assert e1 == one
assert e2 == two
tm.assert_series_equal(three, e3)
def test_multi_iter_frame(self, three_group):
k1 = np.array(["b", "b", "b", "a", "a", "a"])
k2 = np.array(["1", "2", "1", "2", "1", "2"])
df = DataFrame(
{"v1": np.random.randn(6), "v2": np.random.randn(6), "k1": k1, "k2": k2},
index=["one", "two", "three", "four", "five", "six"],
)
grouped = df.groupby(["k1", "k2"])
# things get sorted!
iterated = list(grouped)
idx = df.index
expected = [
("a", "1", df.loc[idx[[4]]]),
("a", "2", df.loc[idx[[3, 5]]]),
("b", "1", df.loc[idx[[0, 2]]]),
("b", "2", df.loc[idx[[1]]]),
]
for i, ((one, two), three) in enumerate(iterated):
e1, e2, e3 = expected[i]
assert e1 == one
assert e2 == two
tm.assert_frame_equal(three, e3)
# don't iterate through groups with no data
df["k1"] = np.array(["b", "b", "b", "a", "a", "a"])
df["k2"] = np.array(["1", "1", "1", "2", "2", "2"])
grouped = df.groupby(["k1", "k2"])
groups = {key: gp for key, gp in grouped}
assert len(groups) == 2
# axis = 1
three_levels = three_group.groupby(["A", "B", "C"]).mean()
grouped = three_levels.T.groupby(axis=1, level=(1, 2))
for key, group in grouped:
pass
def test_dictify(self, df):
dict(iter(df.groupby("A")))
dict(iter(df.groupby(["A", "B"])))
dict(iter(df["C"].groupby(df["A"])))
dict(iter(df["C"].groupby([df["A"], df["B"]])))
dict(iter(df.groupby("A")["C"]))
dict(iter(df.groupby(["A", "B"])["C"]))
def test_groupby_with_small_elem(self):
# GH 8542
# length=2
df = DataFrame(
{"event": ["start", "start"], "change": [1234, 5678]},
index=pd.DatetimeIndex(["2014-09-10", "2013-10-10"]),
)
grouped = df.groupby([pd.Grouper(freq="M"), "event"])
assert len(grouped.groups) == 2
assert grouped.ngroups == 2
assert (Timestamp("2014-09-30"), "start") in grouped.groups
assert (Timestamp("2013-10-31"), "start") in grouped.groups
res = grouped.get_group((Timestamp("2014-09-30"), "start"))
tm.assert_frame_equal(res, df.iloc[[0], :])
res = grouped.get_group((Timestamp("2013-10-31"), "start"))
tm.assert_frame_equal(res, df.iloc[[1], :])
df = DataFrame(
{"event": ["start", "start", "start"], "change": [1234, 5678, 9123]},
index=pd.DatetimeIndex(["2014-09-10", "2013-10-10", "2014-09-15"]),
)
grouped = df.groupby([pd.Grouper(freq="M"), "event"])
assert len(grouped.groups) == 2
assert grouped.ngroups == 2
assert (Timestamp("2014-09-30"), "start") in grouped.groups
assert (Timestamp("2013-10-31"), "start") in grouped.groups
res = grouped.get_group((Timestamp("2014-09-30"), "start"))
tm.assert_frame_equal(res, df.iloc[[0, 2], :])
res = grouped.get_group((Timestamp("2013-10-31"), "start"))
tm.assert_frame_equal(res, df.iloc[[1], :])
# length=3
df = DataFrame(
{"event": ["start", "start", "start"], "change": [1234, 5678, 9123]},
index=pd.DatetimeIndex(["2014-09-10", "2013-10-10", "2014-08-05"]),
)
grouped = df.groupby([pd.Grouper(freq="M"), "event"])
assert len(grouped.groups) == 3
assert grouped.ngroups == 3
assert (Timestamp("2014-09-30"), "start") in grouped.groups
assert (Timestamp("2013-10-31"), "start") in grouped.groups
assert (Timestamp("2014-08-31"), "start") in grouped.groups
res = grouped.get_group((Timestamp("2014-09-30"), "start"))
tm.assert_frame_equal(res, df.iloc[[0], :])
res = grouped.get_group((Timestamp("2013-10-31"), "start"))
tm.assert_frame_equal(res, df.iloc[[1], :])
res = grouped.get_group((Timestamp("2014-08-31"), "start"))
tm.assert_frame_equal(res, df.iloc[[2], :])
def test_grouping_string_repr(self):
# GH 13394
mi = MultiIndex.from_arrays([list("AAB"), list("aba")])
df = DataFrame([[1, 2, 3]], columns=mi)
gr = df.groupby(df[("A", "a")])
result = gr.grouper.groupings[0].__repr__()
expected = "Grouping(('A', 'a'))"
assert result == expected