fulbank/currency.py

   1 class currency(object):
   2     def __init__(self, symbol):
   3         self.symbol = symbol
   4
   5     def sformat(self, amount):
   6         return "%s %s" % (self.symbol, self.format(amount))
   7
   8     def __repr__(self):
   9         return "#<currency %s>" % self.symbol
  10
  11     @property
  12     def zero(self):
  13         return value(0, self)
  14
  15     _known = {}
  16     @classmethod
  17     def define(cls, *args, **kwargs):
  18         self = cls(*args, **kwargs)
  19         cls._known[self.symbol] = self
  20     @classmethod
  21     def get(cls, symbol):
  22         return cls._known[symbol]
  23
  24     def __reduce__(self):
  25         return _currency_restore, (type(self), self.symbol,)
  26 def _currency_restore(cls, symbol):
  27     return cls.get(symbol)
  28
  29 class integral(currency):
  30     def __init__(self, symbol):
  31         super().__init__(symbol)
  32
  33     def format(self, amount):
  34         return "%i" % amount
  35
  36     def parse(self, text):
  37         return value(int(text), self)
  38
  39 class decimal(currency):
  40     def __init__(self, symbol, separator, thseparator, decimals=2):
  41         super().__init__(symbol)
  42         self.separator = separator
  43         self.thseparator = thseparator
  44         self.decimals = decimals
  45
  46     def format(self, amount):
  47         if amount < 0:
  48             return "-" + self.format(-amount)
  49         bias = 10 ** self.decimals
  50         ip = amount // bias
  51         fp = amount - (ip * bias)
  52         return "%i.%0*i" % (ip, self.decimals, fp)
  53
  54     def parse(self, text):
  55         def parse2(text):
  56             p = text.find(self.separator)
  57             bias = 10 ** self.decimals
  58             if p < 0:
  59                 text = text.replace(self.thseparator)
  60                 if not text.isdigit():
  61                     raise ValueError(text)
  62                 return int(text) * bias
  63             else:
  64                 if p != len(text) - 3:
  65                     raise ValueError(text)
  66                 ip = text[:p].replace(self.thseparator, "")
  67                 fp = text[p + 1:]
  68                 if not (ip.isdigit() and fp.isdigit()):
  69                     raise ValueError(text)
  70                 ip = int(ip)
  71                 fp = int(fp)
  72                 if fp >= bias:
  73                     raise ValueError(text)
  74                 return (ip * bias) + fp
  75         if text[0:1] == "-":
  76             return value(-parse2(text[1:]), self)
  77         else:
  78             return value(parse2(text), self)
  79
  80 decimal.define("SEK", ",", " ")
  81 decimal.define("USD", ".", ",")
  82 integral.define("JPY")
  83
  84 class value(object):
  85     __slots__ = ["amount", "currency"]
  86     def __init__(self, amount, currency):
  87         self.amount = int(amount)
  88         self.currency = currency
  89
  90     def __repr__(self):
  91         return "%s %s" % (self.currency.symbol, self.currency.format(self.amount))
  92
  93     def __add__(self, other):
  94         if self.currency != other.currency:
  95             raise ValueError("cannot add %s to %s" % (other.currency.symbol, self.currency.symbol))
  96         return value(int(self.amount + other.amount), self.currency)
  97     def __sub__(self, other):
  98         if self.currency != other.currency:
  99             raise ValueError("cannot subtract %s from %s" % (other.currency.symbol, self.currency.symbol))
 100         return value(int(self.amount - other.amount), self.currency)
 101     def __mul__(self, other):
 102         return value(int(self.amount * other), self.currency)
 103     def __truediv__(self, other):
 104         if self.currency != other.currency:
 105             raise ValueError("cannot divide %s with %s" % (self.currency.symbol, other.currency.symbol))
 106         return self.amount / other.amount
 107     def __floordiv__(self, other):
 108         if self.currency != other.currency:
 109             raise ValueError("cannot divide %s with %s" % (self.currency.symbol, other.currency.symbol))
 110         return self.amount // other.amount
 111     def __mod__(self, other):
 112         if self.currency != other.currency:
 113             raise ValueError("cannot divide %s with %s" % (self.currency.symbol, other.currency.symbol))
 114         return value(int(self.amount % other.amount), self.currency)
 115     def __divmod__(self, other):
 116         if self.currency != other.currency:
 117             raise ValueError("cannot divide %s with %s" % (self.currency.symbol, other.currency.symbol))
 118         return (self.amount // other.amount, value(int(self.amount % other.amount), self.currency))
 119     def __neg__(self):
 120         return value(-self.amount, self.currency)
 121
 122     def __eq__(self, other):
 123         if self.currency != other.currency:
 124             raise ValueError("cannot compare %s with %s" % (self.currency.symbol, other.currency.symbol))
 125         return self.amount == other.amount
 126     def __ne__(self, other):
 127         if self.currency != other.currency:
 128             raise ValueError("cannot compare %s with %s" % (self.currency.symbol, other.currency.symbol))
 129         return self.amount != other.amount
 130     def __lt__(self, other):
 131         if self.currency != other.currency:
 132             raise ValueError("cannot compare %s with %s" % (self.currency.symbol, other.currency.symbol))
 133         return self.amount < other.amount
 134     def __le__(self, other):
 135         if self.currency != other.currency:
 136             raise ValueError("cannot compare %s with %s" % (self.currency.symbol, other.currency.symbol))
 137         return self.amount <= other.amount
 138     def __gt__(self, other):
 139         if self.currency != other.currency:
 140             raise ValueError("cannot compare %s with %s" % (self.currency.symbol, other.currency.symbol))
 141         return self.amount > other.amount
 142     def __ge__(self, other):
 143         if self.currency != other.currency:
 144             raise ValueError("cannot compare %s with %s" % (self.currency.symbol, other.currency.symbol))
 145         return self.amount >= other.amount