def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
python类Rational()的实例源码
def __eq__(a, b):
"""a == b"""
if isinstance(b, Rational):
return (a._numerator == b.numerator and
a._denominator == b.denominator)
if isinstance(b, numbers.Complex) and b.imag == 0:
b = b.real
if isinstance(b, float):
if math.isnan(b) or math.isinf(b):
# comparisons with an infinity or nan should behave in
# the same way for any finite a, so treat a as zero.
return 0.0 == b
else:
return a == a.from_float(b)
else:
# Since a doesn't know how to compare with b, let's give b
# a chance to compare itself with a.
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def __eq__(a, b):
"""a == b"""
if isinstance(b, Rational):
return (a._numerator == b.numerator and
a._denominator == b.denominator)
if isinstance(b, numbers.Complex) and b.imag == 0:
b = b.real
if isinstance(b, float):
if math.isnan(b) or math.isinf(b):
# comparisons with an infinity or nan should behave in
# the same way for any finite a, so treat a as zero.
return 0.0 == b
else:
return a == a.from_float(b)
else:
# Since a doesn't know how to compare with b, let's give b
# a chance to compare itself with a.
return NotImplemented
def _convert_for_comparison(self, other, equality_op=False):
if isinstance(other, Decimal):
return self, other
if isinstance(other, _numbers.Rational):
if not self._is_special:
self = _dec_from_triple(self._sign,
str(int(self._int) * other.denominator),
self._exp)
return self, Decimal(other.numerator)
if equality_op and isinstance(other, _numbers.Complex) and other.imag == 0:
other = other.real
if isinstance(other, float):
context = getcontext()
if equality_op:
context.flags[FloatOperation] = 1
else:
context._raise_error(FloatOperation,
"strict semantics for mixing floats and Decimals are enabled")
return self, Decimal.from_float(other)
return NotImplemented, NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, numbers.Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def _richcmp(self, other, op):
"""Helper for comparison operators, for internal use only.
Implement comparison between a Rational instance `self`, and
either another Rational instance or a float `other`. If
`other` is not a Rational instance or a float, return
NotImplemented. `op` should be one of the six standard
comparison operators.
"""
# convert other to a Rational instance where reasonable.
if isinstance(other, numbers.Rational):
return op(self._numerator * other.denominator,
self._denominator * other.numerator)
if isinstance(other, float):
if math.isnan(other) or math.isinf(other):
return op(0.0, other)
else:
return op(self, self.from_float(other))
else:
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def __eq__(a, b):
"""a == b"""
if isinstance(b, Rational):
return (a._numerator == b.numerator and
a._denominator == b.denominator)
if isinstance(b, numbers.Complex) and b.imag == 0:
b = b.real
if isinstance(b, float):
if math.isnan(b) or math.isinf(b):
# comparisons with an infinity or nan should behave in
# the same way for any finite a, so treat a as zero.
return 0.0 == b
else:
return a == a.from_float(b)
else:
# Since a doesn't know how to compare with b, let's give b
# a chance to compare itself with a.
return NotImplemented
def _richcmp(self, other, op):
"""Helper for comparison operators, for internal use only.
Implement comparison between a Rational instance `self`, and
either another Rational instance or a float `other`. If
`other` is not a Rational instance or a float, return
NotImplemented. `op` should be one of the six standard
comparison operators.
"""
# convert other to a Rational instance where reasonable.
if isinstance(other, Rational):
return op(self._numerator * other.denominator,
self._denominator * other.numerator)
# comparisons with complex should raise a TypeError, for consistency
# with int<->complex, float<->complex, and complex<->complex comparisons.
if isinstance(other, complex):
raise TypeError("no ordering relation is defined for complex numbers")
if isinstance(other, float):
if math.isnan(other) or math.isinf(other):
return op(0.0, other)
else:
return op(self, self.from_float(other))
else:
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def __eq__(a, b):
"""a == b"""
if isinstance(b, Rational):
return (a._numerator == b.numerator and
a._denominator == b.denominator)
if isinstance(b, numbers.Complex) and b.imag == 0:
b = b.real
if isinstance(b, float):
if math.isnan(b) or math.isinf(b):
# comparisons with an infinity or nan should behave in
# the same way for any finite a, so treat a as zero.
return 0.0 == b
else:
return a == a.from_float(b)
else:
# Since a doesn't know how to compare with b, let's give b
# a chance to compare itself with a.
return NotImplemented
def _richcmp(self, other, op):
"""Helper for comparison operators, for internal use only.
Implement comparison between a Rational instance `self`, and
either another Rational instance or a float `other`. If
`other` is not a Rational instance or a float, return
NotImplemented. `op` should be one of the six standard
comparison operators.
"""
# convert other to a Rational instance where reasonable.
if isinstance(other, Rational):
return op(self._numerator * other.denominator,
self._denominator * other.numerator)
# comparisons with complex should raise a TypeError, for consistency
# with int<->complex, float<->complex, and complex<->complex comparisons.
if isinstance(other, complex):
raise TypeError("no ordering relation is defined for complex numbers")
if isinstance(other, float):
if math.isnan(other) or math.isinf(other):
return op(0.0, other)
else:
return op(self, self.from_float(other))
else:
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def __eq__(a, b):
"""a == b"""
if isinstance(b, Rational):
return (a._numerator == b.numerator and
a._denominator == b.denominator)
if isinstance(b, numbers.Complex) and b.imag == 0:
b = b.real
if isinstance(b, float):
if math.isnan(b) or math.isinf(b):
# comparisons with an infinity or nan should behave in
# the same way for any finite a, so treat a as zero.
return 0.0 == b
else:
return a == a.from_float(b)
else:
# Since a doesn't know how to compare with b, let's give b
# a chance to compare itself with a.
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, numbers.Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def _richcmp(self, other, op):
"""Helper for comparison operators, for internal use only.
Implement comparison between a Rational instance `self`, and
either another Rational instance or a float `other`. If
`other` is not a Rational instance or a float, return
NotImplemented. `op` should be one of the six standard
comparison operators.
"""
# convert other to a Rational instance where reasonable.
if isinstance(other, numbers.Rational):
return op(self._numerator * other.denominator,
self._denominator * other.numerator)
if isinstance(other, float):
if math.isnan(other) or math.isinf(other):
return op(0.0, other)
else:
return op(self, self.from_float(other))
else:
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def __eq__(a, b):
"""a == b"""
if isinstance(b, Rational):
return (a._numerator == b.numerator and
a._denominator == b.denominator)
if isinstance(b, numbers.Complex) and b.imag == 0:
b = b.real
if isinstance(b, float):
if math.isnan(b) or math.isinf(b):
# comparisons with an infinity or nan should behave in
# the same way for any finite a, so treat a as zero.
return 0.0 == b
else:
return a == a.from_float(b)
else:
# Since a doesn't know how to compare with b, let's give b
# a chance to compare itself with a.
return NotImplemented
def _richcmp(self, other, op):
"""Helper for comparison operators, for internal use only.
Implement comparison between a Rational instance `self`, and
either another Rational instance or a float `other`. If
`other` is not a Rational instance or a float, return
NotImplemented. `op` should be one of the six standard
comparison operators.
"""
# convert other to a Rational instance where reasonable.
if isinstance(other, Rational):
return op(self._numerator * other.denominator,
self._denominator * other.numerator)
# comparisons with complex should raise a TypeError, for consistency
# with int<->complex, float<->complex, and complex<->complex comparisons.
if isinstance(other, complex):
raise TypeError("no ordering relation is defined for complex numbers")
if isinstance(other, float):
if math.isnan(other) or math.isinf(other):
return op(0.0, other)
else:
return op(self, self.from_float(other))
else:
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, numbers.Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def _richcmp(self, other, op):
"""Helper for comparison operators, for internal use only.
Implement comparison between a Rational instance `self`, and
either another Rational instance or a float `other`. If
`other` is not a Rational instance or a float, return
NotImplemented. `op` should be one of the six standard
comparison operators.
"""
# convert other to a Rational instance where reasonable.
if isinstance(other, numbers.Rational):
return op(self._numerator * other.denominator,
self._denominator * other.numerator)
if isinstance(other, float):
if math.isnan(other) or math.isinf(other):
return op(0.0, other)
else:
return op(self, self.from_float(other))
else:
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def __eq__(a, b):
"""a == b"""
if isinstance(b, Rational):
return (a._numerator == b.numerator and
a._denominator == b.denominator)
if isinstance(b, numbers.Complex) and b.imag == 0:
b = b.real
if isinstance(b, float):
if math.isnan(b) or math.isinf(b):
# comparisons with an infinity or nan should behave in
# the same way for any finite a, so treat a as zero.
return 0.0 == b
else:
return a == a.from_float(b)
else:
# Since a doesn't know how to compare with b, let's give b
# a chance to compare itself with a.
return NotImplemented
def _richcmp(self, other, op):
"""Helper for comparison operators, for internal use only.
Implement comparison between a Rational instance `self`, and
either another Rational instance or a float `other`. If
`other` is not a Rational instance or a float, return
NotImplemented. `op` should be one of the six standard
comparison operators.
"""
# convert other to a Rational instance where reasonable.
if isinstance(other, Rational):
return op(self._numerator * other.denominator,
self._denominator * other.numerator)
# comparisons with complex should raise a TypeError, for consistency
# with int<->complex, float<->complex, and complex<->complex comparisons.
if isinstance(other, complex):
raise TypeError("no ordering relation is defined for complex numbers")
if isinstance(other, float):
if math.isnan(other) or math.isinf(other):
return op(0.0, other)
else:
return op(self, self.from_float(other))
else:
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def __eq__(a, b):
"""a == b"""
if isinstance(b, Rational):
return (a._numerator == b.numerator and
a._denominator == b.denominator)
if isinstance(b, numbers.Complex) and b.imag == 0:
b = b.real
if isinstance(b, float):
if math.isnan(b) or math.isinf(b):
# comparisons with an infinity or nan should behave in
# the same way for any finite a, so treat a as zero.
return 0.0 == b
else:
return a == a.from_float(b)
else:
# Since a doesn't know how to compare with b, let's give b
# a chance to compare itself with a.
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, numbers.Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
def _richcmp(self, other, op):
"""Helper for comparison operators, for internal use only.
Implement comparison between a Rational instance `self`, and
either another Rational instance or a float `other`. If
`other` is not a Rational instance or a float, return
NotImplemented. `op` should be one of the six standard
comparison operators.
"""
# convert other to a Rational instance where reasonable.
if isinstance(other, numbers.Rational):
return op(self._numerator * other.denominator,
self._denominator * other.numerator)
if isinstance(other, float):
if math.isnan(other) or math.isinf(other):
return op(0.0, other)
else:
return op(self, self.from_float(other))
else:
return NotImplemented
def __pow__(a, b):
"""a ** b
If b is not an integer, the result will be a float or complex
since roots are generally irrational. If b is an integer, the
result will be rational.
"""
if isinstance(b, Rational):
if b.denominator == 1:
power = b.numerator
if power >= 0:
return Fraction(a._numerator ** power,
a._denominator ** power)
else:
return Fraction(a._denominator ** -power,
a._numerator ** -power)
else:
# A fractional power will generally produce an
# irrational number.
return float(a) ** float(b)
else:
return float(a) ** b
