[Python-ideas] Pre-conditions and post-conditions

[Jonathan Fine]

Ivan and Steve wrote

>> TBH, I think one of the main points of design by contract is that contracts
>> are verified statically.

> No, that's not correct.

> https://www.eiffel.org/doc/eiffel/ET-_Design_by_Contract_%28tm%29%2C_Assertions_and_Exceptions

The page from Steve supplied (URL above) states

> During development and testing, assertion monitoring should
> be turned on at the highest possible level. Combined with
> static typing and the immediate feedback of compilation techniques
> [...] this permits the development process  [...]
> where errors are exterminated at birth.

Based on the Eiffel docs, I find Ivan's opinion reasonable. He said it
was "one of the main points". The goal is to detect errors
immediately. Run-time assertion monitoring and static typing are two
means towards that end.

Our shared problem and goal is to have similar immediate detection of
errors in Python (when the development process requires that degree of
rigour).

-- 
Jonathan