What guarantees do you get from a compiler than you don't get from a third party tool? > Plus the strangest feature of all - a mechanism for turning off the op

What guarantees do you get from a compiler than you don't get from a third party tool? > Plus the strangest feature of all - a mechanism for turning off the optional type checking so old code will still compile, even if it won't work right. Most languages have this, in some form or another. There are ways to get around type checking when the compiler misunderstands something. How is this unique to python?