def sample_messy_power(variable, entropy):
"""Returns unsimplified power expression like ((x**2)**3/x**4)**2/x**3."""
if entropy <= 0:
return variable
which = random.choice([1, 2, 3])
if which == 1:
exponent_entropy = min(2, entropy)
entropy -= exponent_entropy
exponent = number.integer_or_rational(exponent_entropy, signed=True)
left = sample_messy_power(variable, entropy)
return ops.Pow(left, exponent)
entropy_left = entropy / 2
if entropy_left < 1:
entropy_left = 0
entropy_right = entropy - entropy_left
if random.choice([False, True]):
entropy_left, entropy_right = entropy_right, entropy_left
left = sample_messy_power(variable, entropy_left)
right = sample_messy_power(variable, entropy_right)
if which == 2:
return ops.Mul(left, right)
else:
return ops.Div(left, right)
def testArithmeticLength(self):
"""Tests that the generated arithmetic expressions have given length."""
for _ in range(1000):
target = number.integer_or_rational(4, signed=True)
entropy = 8.0
length = random.randint(2, 10)
expression = arithmetic.arithmetic(target, entropy, length)
# Note: actual length is #ops = #numbers - 1.
actual_length = len(ops.number_constants(expression)) - 1
self.assertEqual(actual_length, length)
def _sub_op(value, sample_args, rationals_allowed):
"""Returns sampled args for `ops.Sub`."""
entropy, sample_args = sample_args.peel()
if rationals_allowed and sample_args.count >= 3:
x = number.integer_or_rational(entropy, True)
else:
x = number.integer(entropy, True)
if random.choice([False, True]):
op_args = [x, x - value]
else:
op_args = [value + x, x]
return ops.Sub, op_args, sample_args
def testArithmetic(self):
for _ in range(1000):
target = number.integer_or_rational(4, signed=True)
entropy = 8.0
expression = arithmetic.arithmetic(target, entropy)
self.assertEqual(sympy.sympify(expression), target)
def integer_or_rational_or_decimal(entropy):
if random.choice([False, True]):
return number.integer_or_decimal(entropy, signed=True)
else:
return number.integer_or_rational(entropy, signed=True)
def testIntegerOrRational(self, signed):
# Tests we can call it. Do it a few times so both code paths get executed.
for _ in range(10):
number.integer_or_rational(2, signed)