Rational with symbol as numerator not working?

[anthonyquizon]

Hello,

I'm testing out the library and tried to create a rational with a symbol as the numerator:

import symengine
A = symengine.Symbol("A")
B = symengine.Rational(A,10)

However, when I try this, I get the following error:

Traceback (most recent call last):                                                                       
  File "<stdin>", line 1, in <module>                                                                    
  File "symengine_wrapper.pyx", line 1586, in symengine.lib.symengine_wrapper.Rational.__new__           
  File "symengine_wrapper.pyx", line 1642, in symengine.lib.symengine_wrapper.Integer.__new__            
  File "symengine_wrapper.pyx", line 1078, in symengine.lib.symengine_wrapper.Basic.__int__              
  File "symengine_wrapper.pyx", line 1072, in symengine.lib.symengine_wrapper.Basic.__float__
  File "symengine_wrapper.pyx", line 921, in symengine.lib.symengine_wrapper.Basic.n                     
  File "symengine_wrapper.pyx", line 4033, in symengine.lib.symengine_wrapper.evalf
RuntimeError: Symbol cannot be evaluated.

II noticed in this issue that evalf for rationals with symbols has been excluded and thatthe error above runs evalf.

So is something like x/1 intentionally restricted from this library?

However, I'm able to create a rational if the symbol is the denominator:

B = symengine.Rational(10,A)

[certik]

I always thought Rational is meant for just numbers. You can create x/1 directly using the division / operator.

[anthonyquizon]

Oh great, thats good to know!

[eric-wieser]

Give this works in sympy, should it not also work in symengine?

[isuruf]

Changing

symengine.py/symengine/lib/symengine_wrapper.pyx

Line 1592 in 740b26f

return Integer(p)/q

to _sympify(p)/q should work.

[certik]

@isuruf should we submit a PR?

[isuruf]

Sure. If someone can send a PR, I'll review.

[certik]

@eric-wieser do you want to send a PR for this?