test_sage.py 文件源码

def check_expression(expr, var_symbols, only_from_sympy=False):
    """
    Does eval(expr) both in Sage and SymPy and does other checks.
    """

    # evaluate the expression in the context of Sage:
    if var_symbols:
        sage.var(var_symbols)
    a = globals().copy()
    # safety checks...
    a.update(sage.__dict__)
    assert "sin" in a
    is_different = False
    try:
        e_sage = eval(expr, a)
        assert not isinstance(e_sage, sympy.Basic)
    except (NameError, TypeError):
        is_different = True
        pass

    # evaluate the expression in the context of SymPy:
    if var_symbols:
        sympy_vars = sympy.var(var_symbols)
    b = globals().copy()
    b.update(sympy.__dict__)
    assert "sin" in b
    b.update(sympy.__dict__)
    e_sympy = eval(expr, b)
    assert isinstance(e_sympy, sympy.Basic)

    # Sympy func may have specific _sage_ method
    if is_different:
        _sage_method = getattr(e_sympy.func, "_sage_")
        e_sage = _sage_method(sympy.S(e_sympy))

    # Do the actual checks:
    if not only_from_sympy:
        assert sympy.S(e_sage) == e_sympy
    assert e_sage == sage.SR(e_sympy)