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bpo-41773: Raise exception for non-finite weights in random.choices(). (GH-22441)

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+23

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Lines changed: 2 additions & 2 deletions

Original file line number	Diff line number	Diff line change
`@@ -180,8 +180,8 @@ Functions for sequences`
`180`	`180`
`181`	`181`	`The weights or cum_weights can use any numeric type that interoperates`
`182`	`182`	with the:class:`float` values returned by:func:`random` (that includes
`183`		`- integers, floats, and fractions but excludes decimals).Behavior is`
`184`		-undefined if any weight is negative. A:exc:`ValueError` is raised if all
	`183`	`+ integers, floats, and fractions but excludes decimals).Weights are assumed`
	`184`	+to be non-negative and finite. A:exc:`ValueError` is raised if all
`185`	`185`	`weights are zero.`
`186`	`186`
`187`	`187`	For a given seed, the:func:`choices` function with equal weighting

Lines changed: 3 additions & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -48,7 +48,7 @@`
`48`	`48`	`fromwarningsimportwarnas_warn`
`49`	`49`	`frommathimportlogas_log,expas_exp,pias_pi,eas_e,ceilas_ceil`
`50`	`50`	`frommathimportsqrtas_sqrt,acosas_acos,cosas_cos,sinas_sin`
`51`		`-frommathimporttauasTWOPI,flooras_floor`
	`51`	`+frommathimporttauasTWOPI,flooras_floor,isfiniteas_isfinite`
`52`	`52`	`fromosimporturandomas_urandom`
`53`	`53`	`from_collections_abcimportSetas_Set,Sequenceas_Sequence`
`54`	`54`	`fromitertoolsimportaccumulateas_accumulate,repeatas_repeat`
`@@ -492,6 +492,8 @@ def choices(self, population, weights=None, *, cum_weights=None, k=1):`
`492`	`492`	`total=cum_weights[-1]+0.0# convert to float`
`493`	`493`	`iftotal<=0.0:`
`494`	`494`	`raiseValueError('Total of weights must be greater than zero')`
	`495`	`+ifnot_isfinite(total):`
	`496`	`+raiseValueError('Total of weights must be finite')`
`495`	`497`	`bisect=_bisect`
`496`	`498`	`hi=n-1`
`497`	`499`	`return [population[bisect(cum_weights,random()*total,0,hi)]`

Lines changed: 16 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -324,6 +324,22 @@ def test_choices_with_all_zero_weights(self):`
`324`	`324`	`withself.assertRaises(ValueError):`
`325`	`325`	`self.gen.choices('AB', [0.0,0.0])`
`326`	`326`
	`327`	`+deftest_choices_negative_total(self):`
	`328`	`+withself.assertRaises(ValueError):`
	`329`	`+self.gen.choices('ABC', [3,-5,1])`
	`330`	`+`
	`331`	`+deftest_choices_infinite_total(self):`
	`332`	`+withself.assertRaises(ValueError):`
	`333`	`+self.gen.choices('A', [float('inf')])`
	`334`	`+withself.assertRaises(ValueError):`
	`335`	`+self.gen.choices('AB', [0.0,float('inf')])`
	`336`	`+withself.assertRaises(ValueError):`
	`337`	`+self.gen.choices('AB', [-float('inf'),123])`
	`338`	`+withself.assertRaises(ValueError):`
	`339`	`+self.gen.choices('AB', [0.0,float('nan')])`
	`340`	`+withself.assertRaises(ValueError):`
	`341`	`+self.gen.choices('AB', [float('-inf'),float('inf')])`
	`342`	`+`
`327`	`343`	`deftest_gauss(self):`
`328`	`344`	`# Ensure that the seed() method initializes all the hidden state. In`
`329`	`345`	`# particular, through 2.2.1 it failed to reset a piece of state used`

Lines changed: 2 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+Note in documentation that:func:`random.choices` doesn't support non-finite
	`2`	+weights, raise:exc:`ValueError` when given non-finite weights.

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