# rational.py, rational number class Reinier Heeres <reinier@heeres.eu>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#
# Change log:
# 2007-07-03: rwh, first version
from decimal import Decimal
import logging
_logger = logging.getLogger('Rational')
class Rational:
def __init__(self, n=None, d=None):
self.n = 0
self.d = 0
if n is not None:
self.set(n, d)
def set(self, n, d=None):
if d is not None:
self.n = int(n)
self.d = int(d)
elif isinstance(n, tuple) or isinstance(n, list):
self.n = int(n[0])
self.d = int(n[1])
elif isinstance(n, bytes):
return
self._simplify()
def __str__(self):
if self.d == 1 or self.d == 0:
return "%d" % (self.n)
else:
return "%d/%d" % (self.n, self.d)
def __float__(self):
return float(self.n) / float(self.d)
def gcd(self, a, b):
if b == 0:
return a
else:
return self.gcd(b, a % b)
def _simplify(self):
if self.d == 0:
return
if self.n == self.d:
self.n = int(1)
self.d = int(1)
else:
gcd = self.gcd(self.n, self.d)
self.n /= gcd
self.d /= gcd
def __add__(self, rval):
if isinstance(rval, Rational):
ret = Rational(self.n * rval.d + self.d * rval.n, self.d * rval.d)
elif isinstance(rval, int) or isinstance(rval,
int):
ret = Rational(self.n + self.d * rval, self.d)
else:
ret = float(self) + rval
return ret
def __radd__(self, lval):
return self.__add__(lval)
def __sub__(self, rval):
if isinstance(rval, Rational):
ret = Rational(self.n * rval.d - self.d * rval.n, self.d * rval.d)
elif isinstance(rval, int) or isinstance(rval,
int):
ret = Rational(self.n - self.d * rval, self.d)
else:
ret = float(self) - rval
return ret
def __rsub__(self, lval):
return -self.__sub__(lval)
def __mul__(self, rval):
if isinstance(rval, Rational):
ret = Rational(self.n * rval.n, self.d * rval.d)
elif isinstance(rval, int) or isinstance(rval,
int):
ret = Rational(self.n * rval, self.d)
elif isinstance(rval, Decimal):
ret = rval * Decimal(str(float(self)))
else:
ret = rval * float(self)
return ret
def __rmul__(self, lval):
return self.__mul__(lval)
def __div__(self, rval):
if isinstance(rval, Rational):
ret = Rational(self.n * rval.d, self.d * rval.n)
elif isinstance(rval, int) or isinstance(rval,
int):
ret = Rational(self.n, self.d * rval)
else:
ret = float(self) / rval
return ret
def __rdiv__(self, lval):
return self.__div__(lval)
def __neg__(self):
return Rational(-self.n, self.d)
def __abs__(self):
self.n = abs(self.n)
self.d = abs(self.d)
def __pow__(self, rval):
if isinstance(rval, int) or isinstance(rval, int):
ret = Rational(self.n ** rval, self.d ** rval)
else:
ret = float(self.n) ** rval / float(self.d) ** rval
return ret