aoc-2022/venv/Lib/site-packages/pandas/tests/series/methods/test_matmul.py

79 lines
2.6 KiB
Python

import operator
import numpy as np
import pytest
from pandas import (
DataFrame,
Series,
)
import pandas._testing as tm
class TestMatmul:
def test_matmul(self):
# matmul test is for GH#10259
a = Series(np.random.randn(4), index=["p", "q", "r", "s"])
b = DataFrame(
np.random.randn(3, 4), index=["1", "2", "3"], columns=["p", "q", "r", "s"]
).T
# Series @ DataFrame -> Series
result = operator.matmul(a, b)
expected = Series(np.dot(a.values, b.values), index=["1", "2", "3"])
tm.assert_series_equal(result, expected)
# DataFrame @ Series -> Series
result = operator.matmul(b.T, a)
expected = Series(np.dot(b.T.values, a.T.values), index=["1", "2", "3"])
tm.assert_series_equal(result, expected)
# Series @ Series -> scalar
result = operator.matmul(a, a)
expected = np.dot(a.values, a.values)
tm.assert_almost_equal(result, expected)
# GH#21530
# vector (1D np.array) @ Series (__rmatmul__)
result = operator.matmul(a.values, a)
expected = np.dot(a.values, a.values)
tm.assert_almost_equal(result, expected)
# GH#21530
# vector (1D list) @ Series (__rmatmul__)
result = operator.matmul(a.values.tolist(), a)
expected = np.dot(a.values, a.values)
tm.assert_almost_equal(result, expected)
# GH#21530
# matrix (2D np.array) @ Series (__rmatmul__)
result = operator.matmul(b.T.values, a)
expected = np.dot(b.T.values, a.values)
tm.assert_almost_equal(result, expected)
# GH#21530
# matrix (2D nested lists) @ Series (__rmatmul__)
result = operator.matmul(b.T.values.tolist(), a)
expected = np.dot(b.T.values, a.values)
tm.assert_almost_equal(result, expected)
# mixed dtype DataFrame @ Series
a["p"] = int(a.p)
result = operator.matmul(b.T, a)
expected = Series(np.dot(b.T.values, a.T.values), index=["1", "2", "3"])
tm.assert_series_equal(result, expected)
# different dtypes DataFrame @ Series
a = a.astype(int)
result = operator.matmul(b.T, a)
expected = Series(np.dot(b.T.values, a.T.values), index=["1", "2", "3"])
tm.assert_series_equal(result, expected)
msg = r"Dot product shape mismatch, \(4,\) vs \(3,\)"
# exception raised is of type Exception
with pytest.raises(Exception, match=msg):
a.dot(a.values[:3])
msg = "matrices are not aligned"
with pytest.raises(ValueError, match=msg):
a.dot(b.T)