class FVal(): """A value to represent numbers for financial applications. At the moment we use the python Decimal library but the abstraction will help us change the underlying implementation if needed. At the moment we do not allow any operations against floating points. Even though floating points could be converted to Decimals before each operation we will use this restriction to make sure floating point numbers are rooted from the codebase first. """ __slots__ = ('num',) def __init__(self, data: AcceptableFValInitInput = 0): try: if isinstance(data, float): self.num = Decimal(str(data)) elif isinstance(data, bytes): # assume it's an ascii string and try to decode the bytes to one self.num = Decimal(data.decode()) elif isinstance(data, bool): # type: ignore # This elif has to come before the isinstance(int) check due to # https://stackoverflow.com/questions/37888620/comparing-boolean-and-int-using-isinstance raise ValueError('Invalid type bool for data given to FVal constructor') elif isinstance(data, (Decimal, int, str)): self.num = Decimal(data) elif isinstance(data, FVal): self.num = data.num else: raise ValueError(f'Invalid type {type(data)} of data given to FVal constructor') except InvalidOperation as e: raise ValueError( 'Expected string, int, float, or Decimal to initialize an FVal.' 'Found {}.'.format(type(data)), ) from e def __str__(self) -> str: return str(self.num) def __repr__(self) -> str: return 'FVal({})'.format(str(self.num)) def __gt__(self, other: AcceptableFValOtherInput) -> bool: evaluated_other = evaluate_input(other) return self.num.compare_signal(evaluated_other) == Decimal('1') def __lt__(self, other: AcceptableFValOtherInput) -> bool: evaluated_other = evaluate_input(other) return self.num.compare_signal(evaluated_other) == Decimal('-1') def __le__(self, other: AcceptableFValOtherInput) -> bool: evaluated_other = evaluate_input(other) return self.num.compare_signal(evaluated_other) in (Decimal('-1'), Decimal('0')) def __ge__(self, other: AcceptableFValOtherInput) -> bool: evaluated_other = evaluate_input(other) return self.num.compare_signal(evaluated_other) in (Decimal('1'), Decimal('0')) def __eq__(self, other: object) -> bool: evaluated_other = evaluate_input(other) return self.num.compare_signal(evaluated_other) == Decimal('0') def __add__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__add__(evaluated_other)) def __sub__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__sub__(evaluated_other)) def __mul__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__mul__(evaluated_other)) def __truediv__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__truediv__(evaluated_other)) def __floordiv__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__floordiv__(evaluated_other)) def __pow__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__pow__(evaluated_other)) def __radd__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__radd__(evaluated_other)) def __rsub__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__rsub__(evaluated_other)) def __rmul__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__rmul__(evaluated_other)) def __rtruediv__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__rtruediv__(evaluated_other)) def __rfloordiv__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__rfloordiv__(evaluated_other)) def __mod__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__mod__(evaluated_other)) def __rmod__(self, other: AcceptableFValOtherInput) -> 'FVal': evaluated_other = evaluate_input(other) return FVal(self.num.__rmod__(evaluated_other)) def __float__(self) -> float: return float(self.num) # --- Unary operands def __neg__(self) -> 'FVal': return FVal(self.num.__neg__()) def __abs__(self) -> 'FVal': return FVal(self.num.copy_abs()) # --- Other operations def fma(self, other: AcceptableFValOtherInput, third: AcceptableFValOtherInput) -> 'FVal': """ Fused multiply-add. Return self*other+third with no rounding of the intermediate product self*other """ evaluated_other = evaluate_input(other) evaluated_third = evaluate_input(third) return FVal(self.num.fma(evaluated_other, evaluated_third)) def to_percentage(self, precision: int = 4, with_perc_sign: bool = True) -> str: return f'{self.num*100:.{precision}f}{"%" if with_perc_sign else ""}' def to_int(self, exact: bool) -> int: """ Tries to convert to int, If `exact` is true then it will convert only if it is a whole decimal number; i.e.: if it has got nothing after the decimal point Raises: ConversionError: If exact was True but the FVal is actually not an exact integer. """ if exact and self.num.to_integral_exact() != self.num: raise ConversionError(f'Tried to ask for exact int from {self.num}') return int(self.num) def is_close(self, other: AcceptableFValInitInput, max_diff: str = "1e-6") -> bool: evaluated_max_diff = FVal(max_diff) if not isinstance(other, FVal): other = FVal(other) diff_num = abs(self.num - other.num) return diff_num <= evaluated_max_diff.num
class FVal(object): """A value to represent numbers for financial applications. At the moment we use the python Decimal library but the abstraction will help us change the underlying implementation if needed. At the moment we do not allow any operations against floating points. Even though floating points could be converted to Decimals before each operation we will use this restriction to make sure floating point numbers are rooted from the codebase first. """ __slots__ = ('num',) def __init__(self, data): try: if isinstance(data, float): self.num = Decimal(str(data)) elif isinstance(data, bytes): # assume it's an ascii string and try to decode the bytes to one self.num = Decimal(data.decode()) elif isinstance(data, (Decimal, int, str)): self.num = Decimal(data) elif isinstance(data, FVal): self.num = data.num else: self.num = None except InvalidOperation: self.num = None if not self.num: raise ValueError( 'Expected string, int, float, or Decimal to initialize an FVal.' 'Found {}.'.format(type(data)) ) def __str__(self): return str(self.num) def __repr__(self): return 'FVal({})'.format(str(self.num)) def __gt__(self, other): other = evaluate_input(other) return self.num.compare_signal(other) == Decimal('1') def __lt__(self, other): other = evaluate_input(other) return self.num.compare_signal(other) == Decimal('-1') def __le__(self, other): other = evaluate_input(other) return self.num.compare_signal(other) in (Decimal('-1'), Decimal('0')) def __ge__(self, other): other = evaluate_input(other) return self.num.compare_signal(other) in (Decimal('1'), Decimal('0')) def __eq__(self, other): other = evaluate_input(other) return self.num.compare_signal(other) == Decimal('0') def __add__(self, other): other = evaluate_input(other) return FVal(self.num.__add__(other)) def __sub__(self, other): other = evaluate_input(other) return FVal(self.num.__sub__(other)) def __mul__(self, other): other = evaluate_input(other) return FVal(self.num.__mul__(other)) def __truediv__(self, other): other = evaluate_input(other) return FVal(self.num.__truediv__(other)) def __floordiv__(self, other): other = evaluate_input(other) return FVal(self.num.__floordiv__(other)) def __pow__(self, other): other = evaluate_input(other) return FVal(self.num.__pow__(other)) def __radd__(self, other): other = evaluate_input(other) return FVal(self.num.__radd__(other)) def __rsub__(self, other): other = evaluate_input(other) return FVal(self.num.__rsub__(other)) def __rmul__(self, other): other = evaluate_input(other) return FVal(self.num.__rmul__(other)) def __rtruediv__(self, other): other = evaluate_input(other) return FVal(self.num.__rtruediv__(other)) def __rfloordiv__(self, other): other = evaluate_input(other) return FVal(self.num.__rfloordiv__(other)) def __float__(self): return float(self.num) # --- Unary operands def __neg__(self): return FVal(self.num.__neg__()) def __abs__(self): return FVal(self.num.copy_abs()) # --- Other oparations def fma(self, other, third): """ Fused multiply-add. Return self*other+third with no rounding of the intermediate product self*other """ other = evaluate_input(other) third = evaluate_input(third) return FVal(self.num.fma(other, third)) def to_percentage(self): return '{:.5%}'.format(self.num) def to_int(self, exact): """Tries to convert to int, If `exact` is true then it will convert only if it is a whole decimal number; i.e.: if it has got nothing after the decimal point""" if exact and self.num.to_integral_exact() != self.num: raise ValueError('Tried to ask for exact int from {}'.format(self.num)) return int(self.num) def is_close(self, other, max_diff="1e-6"): max_diff = FVal(max_diff) if not isinstance(other, FVal): other = FVal(other) diff_num = abs(self.num - other.num) return diff_num <= max_diff.num