np.testing (assertions)

np.testing.{assertEqual, assertArrayEqual, assertAllclose, ...} · AssertionError

The numpy.testing assertion functions. A failing assertion throws AssertionError (also a named export) with NumPy's message layout: header, mismatch counts, the first mismatching indices, the largest absolute and relative differences, and the reprs of ACTUAL and DESIRED.

Returns

namespace object

Example

np.testing.assertArrayEqual([1, 2], [1, 2]);  // passes
let msg = "";
try { np.testing.assertArrayEqual([1, 2, 3], [1, 2, 4]); } catch (e) { msg = e.message; }
msg.split("\n")[1];                             // => "Arrays are not equal"
msg.split("\n")[3];                             // => "Mismatched elements: 1 / 3 (33.3%)"
msg.split("\n")[5];                             // => " [2]: 3 (ACTUAL), 4 (DESIRED)"
msg.split("\n").at(-1);                         // => " DESIRED: array([1, 2, 4])"

np.testing.assertArrayEqual(actual, desired, { errMsg?, verbose?, strict? }) · assertArrayLess(x, y, opts?) · assertArrayCompare(comparison, x, y, opts?)

assertArrayEqual: equal shapes (a 0-d side broadcasts unless strict, which also requires equal dtypes) and equal elements; NaNs and Infs must sit at the same positions. assertArrayLess checks x < y. assertArrayCompare is the shared driver: it takes any element-wise comparison returning a bool array, plus header, precision, equalNan, equalInf, names.

Parameters

actualArrayLike

An NDArray, nested JS array or scalar.

desiredArrayLike

An NDArray, nested JS array or scalar.

Returns

void (throws AssertionError)

Example

np.testing.assertArrayEqual([1, NaN], [1, NaN]);   // passes
np.testing.assertArrayLess([1, 2], [2, 3]);         // passes
np.testing.assertArrayCompare((x, y) => np.lessEqual(x, y), [1, 2], [1, 3]); // passes
np.testing.assertRaises(np.testing.AssertionError, () => np.testing.assertArrayEqual([1, 2], 1, { strict: true })).message.split("\n")[3]; // => "(shapes (2,), () mismatch)"

np.testing.assertArrayEqual(actual: ArrayLike, desired: ArrayLike, opts?: AssertOptions | undefined): void

np.testing.assertAllclose(actual, desired, { rtol=1e-7, atol=0, equalNan=true, errMsg?, verbose?, strict? }) · assertArrayAlmostEqual(actual, desired, { decimal=6 })

assertAllclose checks |actual - desired| <= atol + rtol * |desired| (np.isclose). assertArrayAlmostEqual checks |desired - actual| < 1.5 * 10**-decimal.

Parameters

actualArrayLike

An NDArray, nested JS array or scalar.

desiredArrayLike

An NDArray, nested JS array or scalar.

Returns

void (throws AssertionError)

Example

np.testing.assertAllclose([1, 2], [1, 2 + 1e-8]);  // passes
np.testing.assertArrayAlmostEqual([1, 2], [1, 2.0000001]); // passes
np.testing.assertRaises(np.testing.AssertionError, () => np.testing.assertAllclose([1, 2], [1, 2.1])).message.split("\n")[1]; // => "Not equal to tolerance rtol=1e-07, atol=0"

np.testing.assertAllclose(actual: ArrayLike, desired: ArrayLike, opts?: AllcloseOptions | undefined): void

np.testing.assertEqual(actual, desired, opts?) · assertAlmostEqual(actual, desired, { decimal=7 }) · assertApproxEqual(actual, desired, { significant=7 })

assertEqual compares plain objects and JS arrays recursively (key=/item= lines in the message), NDArrays with assertArrayEqual, and scalars with NaN equal to NaN and 0 different from -0. assertAlmostEqual is the scalar/array decimal check; assertApproxEqual compares scalars to a number of significant digits.

Parameters

actualArrayLike

An NDArray, nested JS array or scalar.

desiredArrayLike

An NDArray, nested JS array or scalar.

Returns

void (throws AssertionError)

Example

np.testing.assertEqual({ a: [1, NaN] }, { a: [1, NaN] }); // passes
np.testing.assertAlmostEqual(1, 1 + 1e-8);                  // passes
np.testing.assertApproxEqual(1234.5, 1234.6, { significant: 4 }); // passes
np.testing.assertRaises(np.testing.AssertionError, () => np.testing.assertEqual([1, 2], [1, 3])).message; // => "\nItems are not equal:\nitem=1\n\n ACTUAL: 2\n DESIRED: 3"

np.testing.assertEqual(actual: unknown, desired: unknown, opts?: AssertOptions | undefined): void

np.testing.assertArrayMaxUlp(a, b, { maxulp=1, dtype? }) · assertArrayAlmostEqualNulp(x, y, nulp=1)

Units-in-the-last-place checks for float arrays. assertArrayMaxUlp returns the ULP distances (shape [1, ...shape], common float dtype) and fails when any exceeds maxulp. assertArrayAlmostEqualNulp checks |x - y| <= nulp * spacing(max(|x|, |y|)). Complex input to assertArrayMaxUlp throws NotImplementedError.

Parameters

aArrayLike

An NDArray, nested JS array or scalar.

bArrayLike

An NDArray, nested JS array or scalar.

Returns

NDArray / void

Example

np.testing.assertArrayMaxUlp([1], [1 + 2 ** -52]);  // => [[1]]
np.testing.assertArrayAlmostEqualNulp([1], [1 + 2 ** -52]); // passes
np.testing.assertRaises(np.testing.AssertionError, () => np.testing.assertArrayMaxUlp([1], [1 + 1e-15])).message; // => "Arrays are not almost equal up to 1 ULP (max difference is 5 ULP)"

np.testing.assertArrayMaxUlp(a: ArrayLike, b: ArrayLike, opts?: MaxUlpOptions | undefined): NDArray

np.testing.assertRaises(ErrorClass, fn, ...args) · assertRaisesRegex(ErrorClass, pattern, fn, ...args) · assert_(val, msg?)

assertRaises calls fn(...args) and returns the error if it is an instance of ErrorClass; other errors propagate, and no error raises AssertionError("<Class> not raised by <fn>"). assertRaisesRegex also searches the message for pattern. assert_ throws AssertionError(msg) for a falsy value (msg may be a function). Async functions are not awaited.

Parameters

ErrorClassclass

Expected error class, e.g. np.ValueError.

fnfunction

Called with args.

Returns

Error

Example

np.testing.assertRaises(np.ShapeError, () => np.zeros(3).reshape([2])).name; // => "ShapeError"
np.testing.assertRaisesRegex(np.ShapeError, "reshape", () => np.zeros(3).reshape([2])).name; // => "ShapeError"
np.testing.assert_(true);   // passes

np.testing.assertRaises<A extends unknown[]>(errorClass: ErrorCtor, fn: (...args: A) => unknown, ...args: A): Error

np.testing.assertWarns(warningType | null, fn, ...args) · assertNoWarnings(fn, ...args)

Node has no Python warnings module; these watch process.emitWarning while fn runs (numera emits RuntimeWarnings there under np.seterr "warn"). Captured warnings are not printed. assertWarns requires at least one warning of warningType (null: any) and returns fn's result; assertNoWarnings requires none.

Parameters

warningTypestring | null

Warning type name, e.g. "RuntimeWarning".

fnfunction

Called with args.

Returns

fn's result

Example

np.testing.assertWarns("RuntimeWarning", () => np.divide([1], [0])).dtype.name; // => "float64"
np.testing.assertNoWarnings(() => np.divide([1], [2]));                // => [0.5]

np.testing.assertStringEqual(actual, desired) · buildErrMsg(arrays, errMsg?, { header, verbose, names, precision }) · printAssertEqual(testString, actual, desired)

assertStringEqual reports a line diff (- actual, + desired). buildErrMsg builds the standard header + ACTUAL/DESIRED message. printAssertEqual deep-compares JS values.

Parameters

actualstring

Actual string.

desiredstring

Desired string.

Returns

void / string

Example

np.testing.buildErrMsg([np.array([1, 2]), 3], "msg"); // => "\nItems are not equal: msg\n ACTUAL: array([1, 2])\n DESIRED: 3"
np.testing.assertStringEqual("abc", "abc");  // passes

np.testing.assertStringEqual(actual: string, desired: string): void