Proper way to assert type of variable in Python

The isinstance built-in is the preferred way if you really must, but even better is to remember Python’s motto: “it’s easier to ask forgiveness than permission”!-) (It was actually Grace Murray Hopper’s favorite motto;-). I.e.: This, BTW, lets the function work just fine on Unicode strings — without any extra effort!-)

Adding message to assert

You are out of luck here. The best way is to define your own assert macro. Basically, it can look like this: This will define the ASSERT macro only if the no-debug macro NDEBUG isn’t defined. Then you’d use it like this: Which is a bit simpler than your usage since you don’t need to … Read more

What is “assert” in JavaScript?

There is no standard assert in JavaScript itself. Perhaps you’re using some library that provides one; for instance, if you’re using Node.js, perhaps you’re using the assertion module. (Browsers and other environments that offer a console implementing the Console API provide console.assert.) The usual meaning of an assert function is to throw an error if the expression passed into the function is false; … Read more

What is the use of “assert” in Python?

The assert statement exists in almost every programming language. It helps detect problems early in your program, where the cause is clear, rather than later when some other operation fails. When you do… … you’re telling the program to test that condition, and immediately trigger an error if the condition is false. In Python, it’s … Read more