[Python-checkins] r54421 - in python/trunk: Doc/api/concrete.tex Doc/lib/libcmath.tex Lib/test/test_cmath.py Misc/NEWS Objects/complexobject.c
georg.brandl
python-checkins at python.org
Sat Mar 17 17:09:00 CET 2007
Author: georg.brandl
Date: Sat Mar 17 17:08:45 2007
New Revision: 54421
Modified:
python/trunk/Doc/api/concrete.tex
python/trunk/Doc/lib/libcmath.tex
python/trunk/Lib/test/test_cmath.py
python/trunk/Misc/NEWS
python/trunk/Objects/complexobject.c
Log:
Patch #1675423: PyComplex_AsCComplex() now tries to convert an object
to complex using its __complex__() method before falling back to the
__float__() method. Therefore, the functions in the cmath module now
can operate on objects that define a __complex__() method.
(backport)
Modified: python/trunk/Doc/api/concrete.tex
==============================================================================
--- python/trunk/Doc/api/concrete.tex (original)
+++ python/trunk/Doc/api/concrete.tex Sat Mar 17 17:08:45 2007
@@ -443,7 +443,9 @@
\begin{cfuncdesc}{double}{PyFloat_AsDouble}{PyObject *pyfloat}
Return a C \ctype{double} representation of the contents of
- \var{pyfloat}.
+ \var{pyfloat}. If \var{pyfloat} is not a Python floating point
+ object but has a \method{__float__} method, this method will first
+ be called to convert \var{pyfloat} into a float.
\end{cfuncdesc}
\begin{cfuncdesc}{double}{PyFloat_AS_DOUBLE}{PyObject *pyfloat}
@@ -558,8 +560,11 @@
\end{cfuncdesc}
\begin{cfuncdesc}{Py_complex}{PyComplex_AsCComplex}{PyObject *op}
- Return the \ctype{Py_complex} value of the complex number
- \var{op}.
+ Return the \ctype{Py_complex} value of the complex number \var{op}.
+ \versionchanged[If \var{op} is not a Python complex number object
+ but has a \method{__complex__} method, this method
+ will first be called to convert \var{op} to a Python
+ complex number object]{2.6}
\end{cfuncdesc}
Modified: python/trunk/Doc/lib/libcmath.tex
==============================================================================
--- python/trunk/Doc/lib/libcmath.tex (original)
+++ python/trunk/Doc/lib/libcmath.tex Sat Mar 17 17:08:45 2007
@@ -5,7 +5,14 @@
\modulesynopsis{Mathematical functions for complex numbers.}
This module is always available. It provides access to mathematical
-functions for complex numbers. The functions are:
+functions for complex numbers. The functions in this module accept
+integers, floating-point numbers or complex numbers as arguments.
+They will also accept any Python object that has either a
+\method{__complex__} or a \method{__float__} method: these methods are
+used to convert the object to a complex or floating-point number, respectively, and
+the function is then applied to the result of the conversion.
+
+The functions are:
\begin{funcdesc}{acos}{x}
Return the arc cosine of \var{x}.
Modified: python/trunk/Lib/test/test_cmath.py
==============================================================================
--- python/trunk/Lib/test/test_cmath.py (original)
+++ python/trunk/Lib/test/test_cmath.py Sat Mar 17 17:08:45 2007
@@ -1,52 +1,196 @@
-#! /usr/bin/env python
-""" Simple test script for cmathmodule.c
- Roger E. Masse
-"""
+from test.test_support import run_unittest
+import unittest
import cmath, math
-from test.test_support import verbose, verify, TestFailed
-verify(abs(cmath.log(10) - math.log(10)) < 1e-9)
-verify(abs(cmath.log(10,2) - math.log(10,2)) < 1e-9)
-try:
- cmath.log('a')
-except TypeError:
- pass
-else:
- raise TestFailed
-
-try:
- cmath.log(10, 'a')
-except TypeError:
- pass
-else:
- raise TestFailed
-
-
-testdict = {'acos' : 1.0,
- 'acosh' : 1.0,
- 'asin' : 1.0,
- 'asinh' : 1.0,
- 'atan' : 0.2,
- 'atanh' : 0.2,
- 'cos' : 1.0,
- 'cosh' : 1.0,
- 'exp' : 1.0,
- 'log' : 1.0,
- 'log10' : 1.0,
- 'sin' : 1.0,
- 'sinh' : 1.0,
- 'sqrt' : 1.0,
- 'tan' : 1.0,
- 'tanh' : 1.0}
-
-for func in testdict.keys():
- f = getattr(cmath, func)
- r = f(testdict[func])
- if verbose:
- print 'Calling %s(%f) = %f' % (func, testdict[func], abs(r))
-
-p = cmath.pi
-e = cmath.e
-if verbose:
- print 'PI = ', abs(p)
- print 'E = ', abs(e)
+class CMathTests(unittest.TestCase):
+ # list of all functions in cmath
+ test_functions = [getattr(cmath, fname) for fname in [
+ 'acos', 'acosh', 'asin', 'asinh', 'atan', 'atanh',
+ 'cos', 'cosh', 'exp', 'log', 'log10', 'sin', 'sinh',
+ 'sqrt', 'tan', 'tanh']]
+ # test first and second arguments independently for 2-argument log
+ test_functions.append(lambda x : cmath.log(x, 1729. + 0j))
+ test_functions.append(lambda x : cmath.log(14.-27j, x))
+
+ def cAssertAlmostEqual(self, a, b, rel_eps = 1e-10, abs_eps = 1e-100):
+ """Check that two complex numbers are almost equal."""
+ # the two complex numbers are considered almost equal if
+ # either the relative error is <= rel_eps or the absolute error
+ # is tiny, <= abs_eps.
+ if a == b == 0:
+ return
+ absolute_error = abs(a-b)
+ relative_error = absolute_error/max(abs(a), abs(b))
+ if relative_error > rel_eps and absolute_error > abs_eps:
+ self.fail("%s and %s are not almost equal" % (a, b))
+
+ def test_constants(self):
+ e_expected = 2.71828182845904523536
+ pi_expected = 3.14159265358979323846
+ self.assertAlmostEqual(cmath.pi, pi_expected, 9,
+ "cmath.pi is %s; should be %s" % (cmath.pi, pi_expected))
+ self.assertAlmostEqual(cmath.e, e_expected, 9,
+ "cmath.e is %s; should be %s" % (cmath.e, e_expected))
+
+ def test_user_object(self):
+ # Test automatic calling of __complex__ and __float__ by cmath
+ # functions
+
+ # some random values to use as test values; we avoid values
+ # for which any of the functions in cmath is undefined
+ # (i.e. 0., 1., -1., 1j, -1j) or would cause overflow
+ cx_arg = 4.419414439 + 1.497100113j
+ flt_arg = -6.131677725
+
+ # a variety of non-complex numbers, used to check that
+ # non-complex return values from __complex__ give an error
+ non_complexes = ["not complex", 1, 5L, 2., None,
+ object(), NotImplemented]
+
+ # Now we introduce a variety of classes whose instances might
+ # end up being passed to the cmath functions
+
+ # usual case: new-style class implementing __complex__
+ class MyComplex(object):
+ def __init__(self, value):
+ self.value = value
+ def __complex__(self):
+ return self.value
+
+ # old-style class implementing __complex__
+ class MyComplexOS:
+ def __init__(self, value):
+ self.value = value
+ def __complex__(self):
+ return self.value
+
+ # classes for which __complex__ raises an exception
+ class SomeException(Exception):
+ pass
+ class MyComplexException(object):
+ def __complex__(self):
+ raise SomeException
+ class MyComplexExceptionOS:
+ def __complex__(self):
+ raise SomeException
+
+ # some classes not providing __float__ or __complex__
+ class NeitherComplexNorFloat(object):
+ pass
+ class NeitherComplexNorFloatOS:
+ pass
+ class MyInt(object):
+ def __int__(self): return 2
+ def __long__(self): return 2L
+ def __index__(self): return 2
+ class MyIntOS:
+ def __int__(self): return 2
+ def __long__(self): return 2L
+ def __index__(self): return 2
+
+ # other possible combinations of __float__ and __complex__
+ # that should work
+ class FloatAndComplex(object):
+ def __float__(self):
+ return flt_arg
+ def __complex__(self):
+ return cx_arg
+ class FloatAndComplexOS:
+ def __float__(self):
+ return flt_arg
+ def __complex__(self):
+ return cx_arg
+ class JustFloat(object):
+ def __float__(self):
+ return flt_arg
+ class JustFloatOS:
+ def __float__(self):
+ return flt_arg
+
+ for f in self.test_functions:
+ # usual usage
+ self.cAssertAlmostEqual(f(MyComplex(cx_arg)), f(cx_arg))
+ self.cAssertAlmostEqual(f(MyComplexOS(cx_arg)), f(cx_arg))
+ # other combinations of __float__ and __complex__
+ self.cAssertAlmostEqual(f(FloatAndComplex()), f(cx_arg))
+ self.cAssertAlmostEqual(f(FloatAndComplexOS()), f(cx_arg))
+ self.cAssertAlmostEqual(f(JustFloat()), f(flt_arg))
+ self.cAssertAlmostEqual(f(JustFloatOS()), f(flt_arg))
+ # TypeError should be raised for classes not providing
+ # either __complex__ or __float__, even if they provide
+ # __int__, __long__ or __index__. An old-style class
+ # currently raises AttributeError instead of a TypeError;
+ # this could be considered a bug.
+ self.assertRaises(TypeError, f, NeitherComplexNorFloat())
+ self.assertRaises(TypeError, f, MyInt())
+ self.assertRaises(Exception, f, NeitherComplexNorFloatOS())
+ self.assertRaises(Exception, f, MyIntOS())
+ # non-complex return value from __complex__ -> TypeError
+ for bad_complex in non_complexes:
+ self.assertRaises(TypeError, f, MyComplex(bad_complex))
+ self.assertRaises(TypeError, f, MyComplexOS(bad_complex))
+ # exceptions in __complex__ should be propagated correctly
+ self.assertRaises(SomeException, f, MyComplexException())
+ self.assertRaises(SomeException, f, MyComplexExceptionOS())
+
+ def test_input_type(self):
+ # ints and longs should be acceptable inputs to all cmath
+ # functions, by virtue of providing a __float__ method
+ for f in self.test_functions:
+ for arg in [2, 2L, 2.]:
+ self.cAssertAlmostEqual(f(arg), f(arg.__float__()))
+
+ # but strings should give a TypeError
+ for f in self.test_functions:
+ for arg in ["a", "long_string", "0", "1j", ""]:
+ self.assertRaises(TypeError, f, arg)
+
+ def test_cmath_matches_math(self):
+ # check that corresponding cmath and math functions are equal
+ # for floats in the appropriate range
+
+ # test_values in (0, 1)
+ test_values = [0.01, 0.1, 0.2, 0.5, 0.9, 0.99]
+
+ # test_values for functions defined on [-1., 1.]
+ unit_interval = test_values + [-x for x in test_values] + \
+ [0., 1., -1.]
+
+ # test_values for log, log10, sqrt
+ positive = test_values + [1.] + [1./x for x in test_values]
+ nonnegative = [0.] + positive
+
+ # test_values for functions defined on the whole real line
+ real_line = [0.] + positive + [-x for x in positive]
+
+ test_functions = {
+ 'acos' : unit_interval,
+ 'asin' : unit_interval,
+ 'atan' : real_line,
+ 'cos' : real_line,
+ 'cosh' : real_line,
+ 'exp' : real_line,
+ 'log' : positive,
+ 'log10' : positive,
+ 'sin' : real_line,
+ 'sinh' : real_line,
+ 'sqrt' : nonnegative,
+ 'tan' : real_line,
+ 'tanh' : real_line}
+
+ for fn, values in test_functions.items():
+ float_fn = getattr(math, fn)
+ complex_fn = getattr(cmath, fn)
+ for v in values:
+ self.cAssertAlmostEqual(float_fn(v), complex_fn(v))
+
+ # test two-argument version of log with various bases
+ for base in [0.5, 2., 10.]:
+ for v in positive:
+ self.cAssertAlmostEqual(cmath.log(v, base), math.log(v, base))
+
+def test_main():
+ run_unittest(CMathTests)
+
+if __name__ == "__main__":
+ test_main()
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS (original)
+++ python/trunk/Misc/NEWS Sat Mar 17 17:08:45 2007
@@ -12,6 +12,11 @@
Core and builtins
-----------------
+- Patch #1675423: PyComplex_AsCComplex() now tries to convert an object
+ to complex using its __complex__() method before falling back to the
+ __float__() method. Therefore, the functions in the cmath module now
+ can operate on objects that define a __complex__() method.
+
- Patch #1623563: allow __class__ assignment for classes with __slots__.
The old and the new class are still required to have the same slot names.
Modified: python/trunk/Objects/complexobject.c
==============================================================================
--- python/trunk/Objects/complexobject.c (original)
+++ python/trunk/Objects/complexobject.c Sat Mar 17 17:08:45 2007
@@ -252,12 +252,59 @@
PyComplex_AsCComplex(PyObject *op)
{
Py_complex cv;
+ PyObject *newop = NULL;
+ static PyObject *complex_str = NULL;
+
+ assert(op);
+ /* If op is already of type PyComplex_Type, return its value */
if (PyComplex_Check(op)) {
return ((PyComplexObject *)op)->cval;
}
+ /* If not, use op's __complex__ method, if it exists */
+
+ /* return -1 on failure */
+ cv.real = -1.;
+ cv.imag = 0.;
+
+ if (PyInstance_Check(op)) {
+ /* this can go away in python 3000 */
+ if (PyObject_HasAttrString(op, "__complex__")) {
+ newop = PyObject_CallMethod(op, "__complex__", NULL);
+ if (!newop)
+ return cv;
+ }
+ /* else try __float__ */
+ } else {
+ PyObject *complexfunc;
+ if (!complex_str) {
+ if (!(complex_str = PyString_FromString("__complex__")))
+ return cv;
+ }
+ complexfunc = _PyType_Lookup(op->ob_type, complex_str);
+ /* complexfunc is a borrowed reference */
+ if (complexfunc) {
+ newop = PyObject_CallFunctionObjArgs(complexfunc, op, NULL);
+ if (!newop)
+ return cv;
+ }
+ }
+
+ if (newop) {
+ if (!PyComplex_Check(newop)) {
+ PyErr_SetString(PyExc_TypeError,
+ "__complex__ should return a complex object");
+ Py_DECREF(newop);
+ return cv;
+ }
+ cv = ((PyComplexObject *)newop)->cval;
+ Py_DECREF(newop);
+ return cv;
+ }
+ /* If neither of the above works, interpret op as a float giving the
+ real part of the result, and fill in the imaginary part as 0. */
else {
+ /* PyFloat_AsDouble will return -1 on failure */
cv.real = PyFloat_AsDouble(op);
- cv.imag = 0.;
return cv;
}
}
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