ai-content-maker/.venv/Lib/site-packages/pandas/tests/reshape/merge/test_join.py

942 lines
32 KiB
Python

import numpy as np
import pytest
import pandas as pd
from pandas import (
Categorical,
DataFrame,
Index,
MultiIndex,
Series,
Timestamp,
concat,
merge,
)
import pandas._testing as tm
from pandas.tests.reshape.merge.test_merge import (
NGROUPS,
N,
get_test_data,
)
class TestJoin:
def setup_method(self):
# aggregate multiple columns
self.df = DataFrame(
{
"key1": get_test_data(),
"key2": get_test_data(),
"data1": np.random.randn(N),
"data2": np.random.randn(N),
}
)
# exclude a couple keys for fun
self.df = self.df[self.df["key2"] > 1]
self.df2 = DataFrame(
{
"key1": get_test_data(n=N // 5),
"key2": get_test_data(ngroups=NGROUPS // 2, n=N // 5),
"value": np.random.randn(N // 5),
}
)
index, data = tm.getMixedTypeDict()
self.target = DataFrame(data, index=index)
# Join on string value
self.source = DataFrame(
{"MergedA": data["A"], "MergedD": data["D"]}, index=data["C"]
)
def test_left_outer_join(self):
joined_key2 = merge(self.df, self.df2, on="key2")
_check_join(self.df, self.df2, joined_key2, ["key2"], how="left")
joined_both = merge(self.df, self.df2)
_check_join(self.df, self.df2, joined_both, ["key1", "key2"], how="left")
def test_right_outer_join(self):
joined_key2 = merge(self.df, self.df2, on="key2", how="right")
_check_join(self.df, self.df2, joined_key2, ["key2"], how="right")
joined_both = merge(self.df, self.df2, how="right")
_check_join(self.df, self.df2, joined_both, ["key1", "key2"], how="right")
def test_full_outer_join(self):
joined_key2 = merge(self.df, self.df2, on="key2", how="outer")
_check_join(self.df, self.df2, joined_key2, ["key2"], how="outer")
joined_both = merge(self.df, self.df2, how="outer")
_check_join(self.df, self.df2, joined_both, ["key1", "key2"], how="outer")
def test_inner_join(self):
joined_key2 = merge(self.df, self.df2, on="key2", how="inner")
_check_join(self.df, self.df2, joined_key2, ["key2"], how="inner")
joined_both = merge(self.df, self.df2, how="inner")
_check_join(self.df, self.df2, joined_both, ["key1", "key2"], how="inner")
def test_handle_overlap(self):
joined = merge(self.df, self.df2, on="key2", suffixes=(".foo", ".bar"))
assert "key1.foo" in joined
assert "key1.bar" in joined
def test_handle_overlap_arbitrary_key(self):
joined = merge(
self.df,
self.df2,
left_on="key2",
right_on="key1",
suffixes=(".foo", ".bar"),
)
assert "key1.foo" in joined
assert "key2.bar" in joined
def test_join_on(self):
target = self.target
source = self.source
merged = target.join(source, on="C")
tm.assert_series_equal(merged["MergedA"], target["A"], check_names=False)
tm.assert_series_equal(merged["MergedD"], target["D"], check_names=False)
# join with duplicates (fix regression from DataFrame/Matrix merge)
df = DataFrame({"key": ["a", "a", "b", "b", "c"]})
df2 = DataFrame({"value": [0, 1, 2]}, index=["a", "b", "c"])
joined = df.join(df2, on="key")
expected = DataFrame(
{"key": ["a", "a", "b", "b", "c"], "value": [0, 0, 1, 1, 2]}
)
tm.assert_frame_equal(joined, expected)
# Test when some are missing
df_a = DataFrame([[1], [2], [3]], index=["a", "b", "c"], columns=["one"])
df_b = DataFrame([["foo"], ["bar"]], index=[1, 2], columns=["two"])
df_c = DataFrame([[1], [2]], index=[1, 2], columns=["three"])
joined = df_a.join(df_b, on="one")
joined = joined.join(df_c, on="one")
assert np.isnan(joined["two"]["c"])
assert np.isnan(joined["three"]["c"])
# merge column not p resent
with pytest.raises(KeyError, match="^'E'$"):
target.join(source, on="E")
# overlap
source_copy = source.copy()
source_copy["A"] = 0
msg = (
"You are trying to merge on float64 and object columns. If "
"you wish to proceed you should use pd.concat"
)
with pytest.raises(ValueError, match=msg):
target.join(source_copy, on="A")
def test_join_on_fails_with_different_right_index(self):
df = DataFrame(
{"a": np.random.choice(["m", "f"], size=3), "b": np.random.randn(3)}
)
df2 = DataFrame(
{"a": np.random.choice(["m", "f"], size=10), "b": np.random.randn(10)},
index=tm.makeCustomIndex(10, 2),
)
msg = r'len\(left_on\) must equal the number of levels in the index of "right"'
with pytest.raises(ValueError, match=msg):
merge(df, df2, left_on="a", right_index=True)
def test_join_on_fails_with_different_left_index(self):
df = DataFrame(
{"a": np.random.choice(["m", "f"], size=3), "b": np.random.randn(3)},
index=tm.makeCustomIndex(3, 2),
)
df2 = DataFrame(
{"a": np.random.choice(["m", "f"], size=10), "b": np.random.randn(10)}
)
msg = r'len\(right_on\) must equal the number of levels in the index of "left"'
with pytest.raises(ValueError, match=msg):
merge(df, df2, right_on="b", left_index=True)
def test_join_on_fails_with_different_column_counts(self):
df = DataFrame(
{"a": np.random.choice(["m", "f"], size=3), "b": np.random.randn(3)}
)
df2 = DataFrame(
{"a": np.random.choice(["m", "f"], size=10), "b": np.random.randn(10)},
index=tm.makeCustomIndex(10, 2),
)
msg = r"len\(right_on\) must equal len\(left_on\)"
with pytest.raises(ValueError, match=msg):
merge(df, df2, right_on="a", left_on=["a", "b"])
@pytest.mark.parametrize("wrong_type", [2, "str", None, np.array([0, 1])])
def test_join_on_fails_with_wrong_object_type(self, wrong_type):
# GH12081 - original issue
# GH21220 - merging of Series and DataFrame is now allowed
# Edited test to remove the Series object from test parameters
df = DataFrame({"a": [1, 1]})
msg = (
"Can only merge Series or DataFrame objects, "
f"a {type(wrong_type)} was passed"
)
with pytest.raises(TypeError, match=msg):
merge(wrong_type, df, left_on="a", right_on="a")
with pytest.raises(TypeError, match=msg):
merge(df, wrong_type, left_on="a", right_on="a")
def test_join_on_pass_vector(self):
expected = self.target.join(self.source, on="C")
del expected["C"]
join_col = self.target.pop("C")
result = self.target.join(self.source, on=join_col)
tm.assert_frame_equal(result, expected)
def test_join_with_len0(self):
# nothing to merge
merged = self.target.join(self.source.reindex([]), on="C")
for col in self.source:
assert col in merged
assert merged[col].isna().all()
merged2 = self.target.join(self.source.reindex([]), on="C", how="inner")
tm.assert_index_equal(merged2.columns, merged.columns)
assert len(merged2) == 0
def test_join_on_inner(self):
df = DataFrame({"key": ["a", "a", "d", "b", "b", "c"]})
df2 = DataFrame({"value": [0, 1]}, index=["a", "b"])
joined = df.join(df2, on="key", how="inner")
expected = df.join(df2, on="key")
expected = expected[expected["value"].notna()]
tm.assert_series_equal(joined["key"], expected["key"])
tm.assert_series_equal(joined["value"], expected["value"], check_dtype=False)
tm.assert_index_equal(joined.index, expected.index)
def test_join_on_singlekey_list(self):
df = DataFrame({"key": ["a", "a", "b", "b", "c"]})
df2 = DataFrame({"value": [0, 1, 2]}, index=["a", "b", "c"])
# corner cases
joined = df.join(df2, on=["key"])
expected = df.join(df2, on="key")
tm.assert_frame_equal(joined, expected)
def test_join_on_series(self):
result = self.target.join(self.source["MergedA"], on="C")
expected = self.target.join(self.source[["MergedA"]], on="C")
tm.assert_frame_equal(result, expected)
def test_join_on_series_buglet(self):
# GH #638
df = DataFrame({"a": [1, 1]})
ds = Series([2], index=[1], name="b")
result = df.join(ds, on="a")
expected = DataFrame({"a": [1, 1], "b": [2, 2]}, index=df.index)
tm.assert_frame_equal(result, expected)
def test_join_index_mixed(self, join_type):
# no overlapping blocks
df1 = DataFrame(index=np.arange(10))
df1["bool"] = True
df1["string"] = "foo"
df2 = DataFrame(index=np.arange(5, 15))
df2["int"] = 1
df2["float"] = 1.0
joined = df1.join(df2, how=join_type)
expected = _join_by_hand(df1, df2, how=join_type)
tm.assert_frame_equal(joined, expected)
joined = df2.join(df1, how=join_type)
expected = _join_by_hand(df2, df1, how=join_type)
tm.assert_frame_equal(joined, expected)
def test_join_index_mixed_overlap(self):
df1 = DataFrame(
{"A": 1.0, "B": 2, "C": "foo", "D": True},
index=np.arange(10),
columns=["A", "B", "C", "D"],
)
assert df1["B"].dtype == np.int64
assert df1["D"].dtype == np.bool_
df2 = DataFrame(
{"A": 1.0, "B": 2, "C": "foo", "D": True},
index=np.arange(0, 10, 2),
columns=["A", "B", "C", "D"],
)
# overlap
joined = df1.join(df2, lsuffix="_one", rsuffix="_two")
expected_columns = [
"A_one",
"B_one",
"C_one",
"D_one",
"A_two",
"B_two",
"C_two",
"D_two",
]
df1.columns = expected_columns[:4]
df2.columns = expected_columns[4:]
expected = _join_by_hand(df1, df2)
tm.assert_frame_equal(joined, expected)
def test_join_empty_bug(self):
# generated an exception in 0.4.3
x = DataFrame()
x.join(DataFrame([3], index=[0], columns=["A"]), how="outer")
def test_join_unconsolidated(self):
# GH #331
a = DataFrame(np.random.randn(30, 2), columns=["a", "b"])
c = Series(np.random.randn(30))
a["c"] = c
d = DataFrame(np.random.randn(30, 1), columns=["q"])
# it works!
a.join(d)
d.join(a)
def test_join_multiindex(self):
index1 = MultiIndex.from_arrays(
[["a", "a", "a", "b", "b", "b"], [1, 2, 3, 1, 2, 3]],
names=["first", "second"],
)
index2 = MultiIndex.from_arrays(
[["b", "b", "b", "c", "c", "c"], [1, 2, 3, 1, 2, 3]],
names=["first", "second"],
)
df1 = DataFrame(data=np.random.randn(6), index=index1, columns=["var X"])
df2 = DataFrame(data=np.random.randn(6), index=index2, columns=["var Y"])
df1 = df1.sort_index(level=0)
df2 = df2.sort_index(level=0)
joined = df1.join(df2, how="outer")
ex_index = Index(index1.values).union(Index(index2.values))
expected = df1.reindex(ex_index).join(df2.reindex(ex_index))
expected.index.names = index1.names
tm.assert_frame_equal(joined, expected)
assert joined.index.names == index1.names
df1 = df1.sort_index(level=1)
df2 = df2.sort_index(level=1)
joined = df1.join(df2, how="outer").sort_index(level=0)
ex_index = Index(index1.values).union(Index(index2.values))
expected = df1.reindex(ex_index).join(df2.reindex(ex_index))
expected.index.names = index1.names
tm.assert_frame_equal(joined, expected)
assert joined.index.names == index1.names
def test_join_inner_multiindex(self, lexsorted_two_level_string_multiindex):
key1 = ["bar", "bar", "bar", "foo", "foo", "baz", "baz", "qux", "qux", "snap"]
key2 = [
"two",
"one",
"three",
"one",
"two",
"one",
"two",
"two",
"three",
"one",
]
data = np.random.randn(len(key1))
data = DataFrame({"key1": key1, "key2": key2, "data": data})
index = lexsorted_two_level_string_multiindex
to_join = DataFrame(
np.random.randn(10, 3), index=index, columns=["j_one", "j_two", "j_three"]
)
joined = data.join(to_join, on=["key1", "key2"], how="inner")
expected = merge(
data,
to_join.reset_index(),
left_on=["key1", "key2"],
right_on=["first", "second"],
how="inner",
sort=False,
)
expected2 = merge(
to_join,
data,
right_on=["key1", "key2"],
left_index=True,
how="inner",
sort=False,
)
tm.assert_frame_equal(joined, expected2.reindex_like(joined))
expected2 = merge(
to_join,
data,
right_on=["key1", "key2"],
left_index=True,
how="inner",
sort=False,
)
expected = expected.drop(["first", "second"], axis=1)
expected.index = joined.index
assert joined.index.is_monotonic_increasing
tm.assert_frame_equal(joined, expected)
# _assert_same_contents(expected, expected2.loc[:, expected.columns])
def test_join_hierarchical_mixed(self):
# GH 2024
df = DataFrame([(1, 2, 3), (4, 5, 6)], columns=["a", "b", "c"])
new_df = df.groupby(["a"]).agg({"b": [np.mean, np.sum]})
other_df = DataFrame([(1, 2, 3), (7, 10, 6)], columns=["a", "b", "d"])
other_df.set_index("a", inplace=True)
# GH 9455, 12219
msg = "merging between different levels is deprecated"
with tm.assert_produces_warning(FutureWarning, match=msg):
result = merge(new_df, other_df, left_index=True, right_index=True)
assert ("b", "mean") in result
assert "b" in result
def test_join_float64_float32(self):
a = DataFrame(np.random.randn(10, 2), columns=["a", "b"], dtype=np.float64)
b = DataFrame(np.random.randn(10, 1), columns=["c"], dtype=np.float32)
joined = a.join(b)
assert joined.dtypes["a"] == "float64"
assert joined.dtypes["b"] == "float64"
assert joined.dtypes["c"] == "float32"
a = np.random.randint(0, 5, 100).astype("int64")
b = np.random.random(100).astype("float64")
c = np.random.random(100).astype("float32")
df = DataFrame({"a": a, "b": b, "c": c})
xpdf = DataFrame({"a": a, "b": b, "c": c})
s = DataFrame(np.random.random(5).astype("float32"), columns=["md"])
rs = df.merge(s, left_on="a", right_index=True)
assert rs.dtypes["a"] == "int64"
assert rs.dtypes["b"] == "float64"
assert rs.dtypes["c"] == "float32"
assert rs.dtypes["md"] == "float32"
xp = xpdf.merge(s, left_on="a", right_index=True)
tm.assert_frame_equal(rs, xp)
def test_join_many_non_unique_index(self):
df1 = DataFrame({"a": [1, 1], "b": [1, 1], "c": [10, 20]})
df2 = DataFrame({"a": [1, 1], "b": [1, 2], "d": [100, 200]})
df3 = DataFrame({"a": [1, 1], "b": [1, 2], "e": [1000, 2000]})
idf1 = df1.set_index(["a", "b"])
idf2 = df2.set_index(["a", "b"])
idf3 = df3.set_index(["a", "b"])
result = idf1.join([idf2, idf3], how="outer")
df_partially_merged = merge(df1, df2, on=["a", "b"], how="outer")
expected = merge(df_partially_merged, df3, on=["a", "b"], how="outer")
result = result.reset_index()
expected = expected[result.columns]
expected["a"] = expected.a.astype("int64")
expected["b"] = expected.b.astype("int64")
tm.assert_frame_equal(result, expected)
df1 = DataFrame({"a": [1, 1, 1], "b": [1, 1, 1], "c": [10, 20, 30]})
df2 = DataFrame({"a": [1, 1, 1], "b": [1, 1, 2], "d": [100, 200, 300]})
df3 = DataFrame({"a": [1, 1, 1], "b": [1, 1, 2], "e": [1000, 2000, 3000]})
idf1 = df1.set_index(["a", "b"])
idf2 = df2.set_index(["a", "b"])
idf3 = df3.set_index(["a", "b"])
result = idf1.join([idf2, idf3], how="inner")
df_partially_merged = merge(df1, df2, on=["a", "b"], how="inner")
expected = merge(df_partially_merged, df3, on=["a", "b"], how="inner")
result = result.reset_index()
tm.assert_frame_equal(result, expected.loc[:, result.columns])
# GH 11519
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),
}
)
s = Series(
np.repeat(np.arange(8), 2), index=np.repeat(np.arange(8), 2), name="TEST"
)
inner = df.join(s, how="inner")
outer = df.join(s, how="outer")
left = df.join(s, how="left")
right = df.join(s, how="right")
tm.assert_frame_equal(inner, outer)
tm.assert_frame_equal(inner, left)
tm.assert_frame_equal(inner, right)
def test_join_sort(self):
left = DataFrame({"key": ["foo", "bar", "baz", "foo"], "value": [1, 2, 3, 4]})
right = DataFrame({"value2": ["a", "b", "c"]}, index=["bar", "baz", "foo"])
joined = left.join(right, on="key", sort=True)
expected = DataFrame(
{
"key": ["bar", "baz", "foo", "foo"],
"value": [2, 3, 1, 4],
"value2": ["a", "b", "c", "c"],
},
index=[1, 2, 0, 3],
)
tm.assert_frame_equal(joined, expected)
# smoke test
joined = left.join(right, on="key", sort=False)
tm.assert_index_equal(joined.index, Index(range(4)), exact=True)
def test_join_mixed_non_unique_index(self):
# GH 12814, unorderable types in py3 with a non-unique index
df1 = DataFrame({"a": [1, 2, 3, 4]}, index=[1, 2, 3, "a"])
df2 = DataFrame({"b": [5, 6, 7, 8]}, index=[1, 3, 3, 4])
result = df1.join(df2)
expected = DataFrame(
{"a": [1, 2, 3, 3, 4], "b": [5, np.nan, 6, 7, np.nan]},
index=[1, 2, 3, 3, "a"],
)
tm.assert_frame_equal(result, expected)
df3 = DataFrame({"a": [1, 2, 3, 4]}, index=[1, 2, 2, "a"])
df4 = DataFrame({"b": [5, 6, 7, 8]}, index=[1, 2, 3, 4])
result = df3.join(df4)
expected = DataFrame(
{"a": [1, 2, 3, 4], "b": [5, 6, 6, np.nan]}, index=[1, 2, 2, "a"]
)
tm.assert_frame_equal(result, expected)
def test_join_non_unique_period_index(self):
# GH #16871
index = pd.period_range("2016-01-01", periods=16, freq="M")
df = DataFrame(list(range(len(index))), index=index, columns=["pnum"])
df2 = concat([df, df])
result = df.join(df2, how="inner", rsuffix="_df2")
expected = DataFrame(
np.tile(np.arange(16, dtype=np.int64).repeat(2).reshape(-1, 1), 2),
columns=["pnum", "pnum_df2"],
index=df2.sort_index().index,
)
tm.assert_frame_equal(result, expected)
def test_mixed_type_join_with_suffix(self):
# GH #916
df = DataFrame(np.random.randn(20, 6), columns=["a", "b", "c", "d", "e", "f"])
df.insert(0, "id", 0)
df.insert(5, "dt", "foo")
grouped = df.groupby("id")
msg = "The default value of numeric_only"
with tm.assert_produces_warning(FutureWarning, match=msg):
mn = grouped.mean()
cn = grouped.count()
# it works!
mn.join(cn, rsuffix="_right")
def test_join_many(self):
df = DataFrame(np.random.randn(10, 6), columns=list("abcdef"))
df_list = [df[["a", "b"]], df[["c", "d"]], df[["e", "f"]]]
joined = df_list[0].join(df_list[1:])
tm.assert_frame_equal(joined, df)
df_list = [df[["a", "b"]][:-2], df[["c", "d"]][2:], df[["e", "f"]][1:9]]
def _check_diff_index(df_list, result, exp_index):
reindexed = [x.reindex(exp_index) for x in df_list]
expected = reindexed[0].join(reindexed[1:])
tm.assert_frame_equal(result, expected)
# different join types
joined = df_list[0].join(df_list[1:], how="outer")
_check_diff_index(df_list, joined, df.index)
joined = df_list[0].join(df_list[1:])
_check_diff_index(df_list, joined, df_list[0].index)
joined = df_list[0].join(df_list[1:], how="inner")
_check_diff_index(df_list, joined, df.index[2:8])
msg = "Joining multiple DataFrames only supported for joining on index"
with pytest.raises(ValueError, match=msg):
df_list[0].join(df_list[1:], on="a")
def test_join_many_mixed(self):
df = DataFrame(np.random.randn(8, 4), columns=["A", "B", "C", "D"])
df["key"] = ["foo", "bar"] * 4
df1 = df.loc[:, ["A", "B"]]
df2 = df.loc[:, ["C", "D"]]
df3 = df.loc[:, ["key"]]
result = df1.join([df2, df3])
tm.assert_frame_equal(result, df)
def test_join_dups(self):
# joining dups
df = concat(
[
DataFrame(np.random.randn(10, 4), columns=["A", "A", "B", "B"]),
DataFrame(
np.random.randint(0, 10, size=20).reshape(10, 2), columns=["A", "C"]
),
],
axis=1,
)
expected = concat([df, df], axis=1)
result = df.join(df, rsuffix="_2")
result.columns = expected.columns
tm.assert_frame_equal(result, expected)
# GH 4975, invalid join on dups
w = DataFrame(np.random.randn(4, 2), columns=["x", "y"])
x = DataFrame(np.random.randn(4, 2), columns=["x", "y"])
y = DataFrame(np.random.randn(4, 2), columns=["x", "y"])
z = DataFrame(np.random.randn(4, 2), columns=["x", "y"])
dta = x.merge(y, left_index=True, right_index=True).merge(
z, left_index=True, right_index=True, how="outer"
)
with tm.assert_produces_warning(FutureWarning):
dta = dta.merge(w, left_index=True, right_index=True)
expected = concat([x, y, z, w], axis=1)
expected.columns = ["x_x", "y_x", "x_y", "y_y", "x_x", "y_x", "x_y", "y_y"]
tm.assert_frame_equal(dta, expected)
def test_join_multi_to_multi(self, join_type):
# GH 20475
leftindex = MultiIndex.from_product(
[list("abc"), list("xy"), [1, 2]], names=["abc", "xy", "num"]
)
left = DataFrame({"v1": range(12)}, index=leftindex)
rightindex = MultiIndex.from_product(
[list("abc"), list("xy")], names=["abc", "xy"]
)
right = DataFrame({"v2": [100 * i for i in range(1, 7)]}, index=rightindex)
result = left.join(right, on=["abc", "xy"], how=join_type)
expected = (
left.reset_index()
.merge(right.reset_index(), on=["abc", "xy"], how=join_type)
.set_index(["abc", "xy", "num"])
)
tm.assert_frame_equal(expected, result)
msg = r'len\(left_on\) must equal the number of levels in the index of "right"'
with pytest.raises(ValueError, match=msg):
left.join(right, on="xy", how=join_type)
with pytest.raises(ValueError, match=msg):
right.join(left, on=["abc", "xy"], how=join_type)
def test_join_on_tz_aware_datetimeindex(self):
# GH 23931, 26335
df1 = DataFrame(
{
"date": pd.date_range(
start="2018-01-01", periods=5, tz="America/Chicago"
),
"vals": list("abcde"),
}
)
df2 = DataFrame(
{
"date": pd.date_range(
start="2018-01-03", periods=5, tz="America/Chicago"
),
"vals_2": list("tuvwx"),
}
)
result = df1.join(df2.set_index("date"), on="date")
expected = df1.copy()
expected["vals_2"] = Series([np.nan] * 2 + list("tuv"), dtype=object)
tm.assert_frame_equal(result, expected)
def test_join_datetime_string(self):
# GH 5647
dfa = DataFrame(
[
["2012-08-02", "L", 10],
["2012-08-02", "J", 15],
["2013-04-06", "L", 20],
["2013-04-06", "J", 25],
],
columns=["x", "y", "a"],
)
dfa["x"] = pd.to_datetime(dfa["x"])
dfb = DataFrame(
[["2012-08-02", "J", 1], ["2013-04-06", "L", 2]],
columns=["x", "y", "z"],
index=[2, 4],
)
dfb["x"] = pd.to_datetime(dfb["x"])
result = dfb.join(dfa.set_index(["x", "y"]), on=["x", "y"])
expected = DataFrame(
[
[Timestamp("2012-08-02 00:00:00"), "J", 1, 15],
[Timestamp("2013-04-06 00:00:00"), "L", 2, 20],
],
index=[2, 4],
columns=["x", "y", "z", "a"],
)
tm.assert_frame_equal(result, expected)
def test_join_with_categorical_index(self):
# GH47812
ix = ["a", "b"]
id1 = pd.CategoricalIndex(ix, categories=ix)
id2 = pd.CategoricalIndex(reversed(ix), categories=reversed(ix))
df1 = DataFrame({"c1": ix}, index=id1)
df2 = DataFrame({"c2": reversed(ix)}, index=id2)
result = df1.join(df2)
expected = DataFrame(
{"c1": ["a", "b"], "c2": ["a", "b"]},
index=pd.CategoricalIndex(["a", "b"], categories=["a", "b"]),
)
tm.assert_frame_equal(result, expected)
def _check_join(left, right, result, join_col, how="left", lsuffix="_x", rsuffix="_y"):
# some smoke tests
for c in join_col:
assert result[c].notna().all()
left_grouped = left.groupby(join_col)
right_grouped = right.groupby(join_col)
for group_key, group in result.groupby(
join_col if len(join_col) > 1 else join_col[0]
):
l_joined = _restrict_to_columns(group, left.columns, lsuffix)
r_joined = _restrict_to_columns(group, right.columns, rsuffix)
try:
lgroup = left_grouped.get_group(group_key)
except KeyError as err:
if how in ("left", "inner"):
raise AssertionError(
f"key {group_key} should not have been in the join"
) from err
_assert_all_na(l_joined, left.columns, join_col)
else:
_assert_same_contents(l_joined, lgroup)
try:
rgroup = right_grouped.get_group(group_key)
except KeyError as err:
if how in ("right", "inner"):
raise AssertionError(
f"key {group_key} should not have been in the join"
) from err
_assert_all_na(r_joined, right.columns, join_col)
else:
_assert_same_contents(r_joined, rgroup)
def _restrict_to_columns(group, columns, suffix):
found = [
c for c in group.columns if c in columns or c.replace(suffix, "") in columns
]
# filter
group = group.loc[:, found]
# get rid of suffixes, if any
group = group.rename(columns=lambda x: x.replace(suffix, ""))
# put in the right order...
group = group.loc[:, columns]
return group
def _assert_same_contents(join_chunk, source):
NA_SENTINEL = -1234567 # drop_duplicates not so NA-friendly...
jvalues = join_chunk.fillna(NA_SENTINEL).drop_duplicates().values
svalues = source.fillna(NA_SENTINEL).drop_duplicates().values
rows = {tuple(row) for row in jvalues}
assert len(rows) == len(source)
assert all(tuple(row) in rows for row in svalues)
def _assert_all_na(join_chunk, source_columns, join_col):
for c in source_columns:
if c in join_col:
continue
assert join_chunk[c].isna().all()
def _join_by_hand(a, b, how="left"):
join_index = a.index.join(b.index, how=how)
a_re = a.reindex(join_index)
b_re = b.reindex(join_index)
result_columns = a.columns.append(b.columns)
for col, s in b_re.items():
a_re[col] = s
return a_re.reindex(columns=result_columns)
def test_join_inner_multiindex_deterministic_order():
# GH: 36910
left = DataFrame(
data={"e": 5},
index=MultiIndex.from_tuples([(1, 2, 4)], names=("a", "b", "d")),
)
right = DataFrame(
data={"f": 6}, index=MultiIndex.from_tuples([(2, 3)], names=("b", "c"))
)
result = left.join(right, how="inner")
expected = DataFrame(
{"e": [5], "f": [6]},
index=MultiIndex.from_tuples([(2, 1, 4, 3)], names=("b", "a", "d", "c")),
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
("input_col", "output_cols"), [("b", ["a", "b"]), ("a", ["a_x", "a_y"])]
)
def test_join_cross(input_col, output_cols):
# GH#5401
left = DataFrame({"a": [1, 3]})
right = DataFrame({input_col: [3, 4]})
result = left.join(right, how="cross", lsuffix="_x", rsuffix="_y")
expected = DataFrame({output_cols[0]: [1, 1, 3, 3], output_cols[1]: [3, 4, 3, 4]})
tm.assert_frame_equal(result, expected)
def test_join_multiindex_one_level(join_type):
# GH#36909
left = DataFrame(
data={"c": 3}, index=MultiIndex.from_tuples([(1, 2)], names=("a", "b"))
)
right = DataFrame(data={"d": 4}, index=MultiIndex.from_tuples([(2,)], names=("b",)))
result = left.join(right, how=join_type)
expected = DataFrame(
{"c": [3], "d": [4]},
index=MultiIndex.from_tuples([(2, 1)], names=["b", "a"]),
)
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"categories, values",
[
(["Y", "X"], ["Y", "X", "X"]),
([2, 1], [2, 1, 1]),
([2.5, 1.5], [2.5, 1.5, 1.5]),
(
[Timestamp("2020-12-31"), Timestamp("2019-12-31")],
[Timestamp("2020-12-31"), Timestamp("2019-12-31"), Timestamp("2019-12-31")],
),
],
)
def test_join_multiindex_not_alphabetical_categorical(categories, values):
# GH#38502
left = DataFrame(
{
"first": ["A", "A"],
"second": Categorical(categories, categories=categories),
"value": [1, 2],
}
).set_index(["first", "second"])
right = DataFrame(
{
"first": ["A", "A", "B"],
"second": Categorical(values, categories=categories),
"value": [3, 4, 5],
}
).set_index(["first", "second"])
result = left.join(right, lsuffix="_left", rsuffix="_right")
expected = DataFrame(
{
"first": ["A", "A"],
"second": Categorical(categories, categories=categories),
"value_left": [1, 2],
"value_right": [3, 4],
}
).set_index(["first", "second"])
tm.assert_frame_equal(result, expected)
@pytest.mark.parametrize(
"left_empty, how, exp",
[
(False, "left", "left"),
(False, "right", "empty"),
(False, "inner", "empty"),
(False, "outer", "left"),
(False, "cross", "empty"),
(True, "left", "empty"),
(True, "right", "right"),
(True, "inner", "empty"),
(True, "outer", "right"),
(True, "cross", "empty"),
],
)
def test_join_empty(left_empty, how, exp):
left = DataFrame({"A": [2, 1], "B": [3, 4]}, dtype="int64").set_index("A")
right = DataFrame({"A": [1], "C": [5]}, dtype="int64").set_index("A")
if left_empty:
left = left.head(0)
else:
right = right.head(0)
result = left.join(right, how=how)
if exp == "left":
expected = DataFrame({"A": [2, 1], "B": [3, 4], "C": [np.nan, np.nan]})
expected = expected.set_index("A")
elif exp == "right":
expected = DataFrame({"B": [np.nan], "A": [1], "C": [5]})
expected = expected.set_index("A")
elif exp == "empty":
expected = DataFrame(index=Index([]), columns=["B", "C"], dtype="int64")
if how != "cross":
expected = expected.rename_axis("A")
tm.assert_frame_equal(result, expected)