Coverage for /usr/lib/python3/dist-packages/sympy/polys/domains/pythonrationalfield.py: 52%

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

2 

3 

4from sympy.polys.domains.groundtypes import PythonInteger, PythonRational, SymPyRational 

5from sympy.polys.domains.rationalfield import RationalField 

6from sympy.polys.polyerrors import CoercionFailed 

7from sympy.utilities import public 

8 

9@public 

10class PythonRationalField(RationalField): 

11 """Rational field based on :ref:`MPQ`. 

12 

13 This will be used as :ref:`QQ` if ``gmpy`` and ``gmpy2`` are not 

14 installed. Elements are instances of :ref:`MPQ`. 

15 """ 

16 

17 dtype = PythonRational 

18 zero = dtype(0) 

19 one = dtype(1) 

20 alias = 'QQ_python' 

21 

22 def __init__(self): 

23 pass 

24 

25 def get_ring(self): 

26 """Returns ring associated with ``self``. """ 

27 from sympy.polys.domains import PythonIntegerRing 

28 return PythonIntegerRing() 

29 

30 def to_sympy(self, a): 

31 """Convert `a` to a SymPy object. """ 

32 return SymPyRational(a.numerator, a.denominator) 

33 

34 def from_sympy(self, a): 

35 """Convert SymPy's Rational to `dtype`. """ 

36 if a.is_Rational: 

37 return PythonRational(a.p, a.q) 

38 elif a.is_Float: 

39 from sympy.polys.domains import RR 

40 p, q = RR.to_rational(a) 

41 return PythonRational(int(p), int(q)) 

42 else: 

43 raise CoercionFailed("expected `Rational` object, got %s" % a) 

44 

45 def from_ZZ_python(K1, a, K0): 

46 """Convert a Python `int` object to `dtype`. """ 

47 return PythonRational(a) 

48 

49 def from_QQ_python(K1, a, K0): 

50 """Convert a Python `Fraction` object to `dtype`. """ 

51 return a 

52 

53 def from_ZZ_gmpy(K1, a, K0): 

54 """Convert a GMPY `mpz` object to `dtype`. """ 

55 return PythonRational(PythonInteger(a)) 

56 

57 def from_QQ_gmpy(K1, a, K0): 

58 """Convert a GMPY `mpq` object to `dtype`. """ 

59 return PythonRational(PythonInteger(a.numer()), 

60 PythonInteger(a.denom())) 

61 

62 def from_RealField(K1, a, K0): 

63 """Convert a mpmath `mpf` object to `dtype`. """ 

64 p, q = K0.to_rational(a) 

65 return PythonRational(int(p), int(q)) 

66 

67 def numer(self, a): 

68 """Returns numerator of `a`. """ 

69 return a.numerator 

70 

71 def denom(self, a): 

72 """Returns denominator of `a`. """ 

73 return a.denominator