# polynomial ring instance check

Hi there, folks. How do i check if something is an instance of a polynomial ring (univariate or multivariate)?

polynomial ring instance check

add a comment

2

First of all, do you really need to? Just allow any input, if it does not have the methods you are calling then you will get a suitable `AttributeError`

exception thrown. AKA duck-typing.

If you are sure that you actually have to check the type, use the convenience functions:

```
sage: from sage.rings.polynomial.polynomial_ring import is_PolynomialRing
sage: is_PolynomialRing('string')
False
sage: from sage.rings.polynomial.multi_polynomial_ring import is_MPolynomialRing
sage: is_MPolynomialRing('string')
False
```

Asked: **
2012-01-18 10:32:10 -0600
**

Seen: **85 times**

Last updated: **Jan 18 '12**

How to flatten polynomial rings?

What is the best way to work with ratios of polynomials?

Implementing the AKS primality test

Problems with computing discriminants and resultants.

complex, real, common ring, crash in 'vector' constructor

Defining Polynomial Basis and Generic Polynomials

TypeError: non-integral exponents not supported

Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.