Source code for

"""Implementation of :class:`PythonRationalField` class. """

from __future__ import print_function, division

from import RationalField
from import PythonInteger, PythonRational, SymPyRational

from sympy.polys.polyerrors import CoercionFailed
from sympy.utilities import public

[docs]class PythonRationalField(RationalField): """Rational field based on Python rational number type. """ dtype = PythonRational zero = dtype(0) one = dtype(1) alias = 'QQ_python' def __init__(self): pass def get_ring(self): """Returns ring associated with ``self``. """ from import PythonIntegerRing return PythonIntegerRing() def to_sympy(self, a): """Convert `a` to a SymPy object. """ return SymPyRational(a.numerator, a.denominator) def from_sympy(self, a): """Convert SymPy's Rational to `dtype`. """ if a.is_Rational: return PythonRational(a.p, a.q) elif a.is_Float: from import RR p, q = RR.to_rational(a) return PythonRational(int(p), int(q)) else: raise CoercionFailed("expected `Rational` object, got %s" % a) def from_ZZ_python(K1, a, K0): """Convert a Python `int` object to `dtype`. """ return PythonRational(a) def from_QQ_python(K1, a, K0): """Convert a Python `Fraction` object to `dtype`. """ return a def from_ZZ_gmpy(K1, a, K0): """Convert a GMPY `mpz` object to `dtype`. """ return PythonRational(PythonInteger(a)) def from_QQ_gmpy(K1, a, K0): """Convert a GMPY `mpq` object to `dtype`. """ return PythonRational(PythonInteger(a.numer()), PythonInteger(a.denom())) def from_RealField(K1, a, K0): """Convert a mpmath `mpf` object to `dtype`. """ p, q = K0.to_rational(a) return PythonRational(int(p), int(q)) def numer(self, a): """Returns numerator of `a`. """ return a.numerator def denom(self, a): """Returns denominator of `a`. """ return a.denominator