import operator
import numpy as np
import pytest
from pandas._libs.tslibs import IncompatibleFrequency
import pandas as pd
from pandas import Series
import pandas._testing as tm
def _permute(obj):
return obj.take(np.random.permutation(len(obj)))
class TestSeriesFlexArithmetic:
@pytest.mark.parametrize(
"ts",
[
(lambda x: x, lambda x: x * 2, False),
(lambda x: x, lambda x: x[::2], False),
(lambda x: x, lambda x: 5, True),
(lambda x: tm.makeFloatSeries(), lambda x: tm.makeFloatSeries(), True),
],
)
@pytest.mark.parametrize(
"opname", ["add", "sub", "mul", "floordiv", "truediv", "pow"]
)
def test_flex_method_equivalence(self, opname, ts):
# check that Series.{opname} behaves like Series.__{opname}__,
tser = tm.makeTimeSeries().rename("ts")
series = ts[0](tser)
other = ts[1](tser)
check_reverse = ts[2]
op = getattr(Series, opname)
alt = getattr(operator, opname)
result = op(series, other)
expected = alt(series, other)
tm.assert_almost_equal(result, expected)
if check_reverse:
rop = getattr(Series, "r" + opname)
result = rop(series, other)
expected = alt(other, series)
tm.assert_almost_equal(result, expected)
def test_flex_method_subclass_metadata_preservation(self, all_arithmetic_operators):
# GH 13208
class MySeries(Series):
_metadata = ["x"]
@property
def _constructor(self):
return MySeries
opname = all_arithmetic_operators
op = getattr(Series, opname)
m = MySeries([1, 2, 3], name="test")
m.x = 42
result = op(m, 1)
assert result.x == 42
class TestSeriesArithmetic:
# Some of these may end up in tests/arithmetic, but are not yet sorted
def test_add_series_with_period_index(self):
rng = pd.period_range("1/1/2000", "1/1/2010", freq="A")
ts = Series(np.random.randn(len(rng)), index=rng)
result = ts + ts[::2]
expected = ts + ts
expected[1::2] = np.nan
tm.assert_series_equal(result, expected)
result = ts + _permute(ts[::2])
tm.assert_series_equal(result, expected)
msg = "Input has different freq=D from PeriodIndex\\(freq=A-DEC\\)"
with pytest.raises(IncompatibleFrequency, match=msg):
ts + ts.asfreq("D", how="end")
@pytest.mark.parametrize(
"target_add,input_value,expected_value",
[
("!", ["hello", "world"], ["hello!", "world!"]),
("m", ["hello", "world"], ["hellom", "worldm"]),
],
)
def test_string_addition(self, target_add, input_value, expected_value):
# GH28658 - ensure adding 'm' does not raise an error
a = Series(input_value)
result = a + target_add
expected = Series(expected_value)
tm.assert_series_equal(result, expected)
# ------------------------------------------------------------------
# Comparisons
class TestSeriesFlexComparison:
def test_comparison_flex_basic(self):
left = pd.Series(np.random.randn(10))
right = pd.Series(np.random.randn(10))
tm.assert_series_equal(left.eq(right), left == right)
tm.assert_series_equal(left.ne(right), left != right)
tm.assert_series_equal(left.le(right), left < right)
tm.assert_series_equal(left.lt(right), left <= right)
tm.assert_series_equal(left.gt(right), left > right)
tm.assert_series_equal(left.ge(right), left >= right)
# axis
for axis in [0, None, "index"]:
tm.assert_series_equal(left.eq(right, axis=axis), left == right)
tm.assert_series_equal(left.ne(right, axis=axis), left != right)
tm.assert_series_equal(left.le(right, axis=axis), left < right)
tm.assert_series_equal(left.lt(right, axis=axis), left <= right)
tm.assert_series_equal(left.gt(right, axis=axis), left > right)
tm.assert_series_equal(left.ge(right, axis=axis), left >= right)
#
msg = "No axis named 1 for object type"
for op in ["eq", "ne", "le", "le", "gt", "ge"]:
with pytest.raises(ValueError, match=msg):
getattr(left, op)(right, axis=1)
class TestSeriesComparison:
def test_comparison_different_length(self):
a = Series(["a", "b", "c"])
b = Series(["b", "a"])
with pytest.raises(ValueError):
a < b
a = Series([1, 2])
b = Series([2, 3, 4])
with pytest.raises(ValueError):
a == b
@pytest.mark.parametrize("opname", ["eq", "ne", "gt", "lt", "ge", "le"])
def test_ser_flex_cmp_return_dtypes(self, opname):
# GH#15115
ser = Series([1, 3, 2], index=range(3))
const = 2
result = getattr(ser, opname)(const).dtypes
expected = np.dtype("bool")
assert result == expected
@pytest.mark.parametrize("opname", ["eq", "ne", "gt", "lt", "ge", "le"])
def test_ser_flex_cmp_return_dtypes_empty(self, opname):
# GH#15115 empty Series case
ser = Series([1, 3, 2], index=range(3))
empty = ser.iloc[:0]
const = 2
result = getattr(empty, opname)(const).dtypes
expected = np.dtype("bool")
assert result == expected
@pytest.mark.parametrize(
"op",
[operator.eq, operator.ne, operator.le, operator.lt, operator.ge, operator.gt],
)
@pytest.mark.parametrize(
"names", [(None, None, None), ("foo", "bar", None), ("baz", "baz", "baz")]
)
def test_ser_cmp_result_names(self, names, op):
# datetime64 dtype
dti = pd.date_range("1949-06-07 03:00:00", freq="H", periods=5, name=names[0])
ser = Series(dti).rename(names[1])
result = op(ser, dti)
assert result.name == names[2]
# datetime64tz dtype
dti = dti.tz_localize("US/Central")
ser = Series(dti).rename(names[1])
result = op(ser, dti)
assert result.name == names[2]
# timedelta64 dtype
tdi = dti - dti.shift(1)
ser = Series(tdi).rename(names[1])
result = op(ser, tdi)
assert result.name == names[2]
# interval dtype
if op in [operator.eq, operator.ne]:
# interval dtype comparisons not yet implemented
ii = pd.interval_range(start=0, periods=5, name=names[0])
ser = Series(ii).rename(names[1])
result = op(ser, ii)
assert result.name == names[2]
# categorical
if op in [operator.eq, operator.ne]:
# categorical dtype comparisons raise for inequalities
cidx = tdi.astype("category")
ser = Series(cidx).rename(names[1])
result = op(ser, cidx)
assert result.name == names[2]