'' in CC fails

[G. M.-S.]

This works:

sage: for i in [ZZ,QQ,RR]:

....:     print('empty string in',i,':','' in i)

....: 

empty string in Integer Ring : False

empty string in Rational Field : False

empty string in Real Field with 53 bits of precision : False

This gives an error:

sage: '' in CC

[…]

    

    ^

SyntaxError: invalid syntax

Why?

TIA,

Guillermo

[Nils Bruin]

On Wednesday, 3 May 2023 at 08:11:25 UTC-7 G. M.-S. wrote:

This gives an error:

sage: '' in CC

[…]

    

    ^

SyntaxError: invalid syntax

It looks like this error comes from the fact that "eval('')" raises this.  Apparently an empty string is not valid python for the parser. It is a little strange that an empty string is getting parsed to test for membership in CC. Many non-empty strings that are invalid python code do return "False", so it looks like the empty string ends up in a wrong code path somewhere. Worth a bug report, I'd say.

[G. M.-S.]

Thanks Nils.

This is now

https://github.com/sagemath/sage/issues/35607

Guillermo