How do I check if a value is NaN in Python?

I know that float(‘nan’) can be used to represent a NaN (Not a Number) value in Python, but I’m unsure how to check whether a given variable is actually NaN.

Using a comparison like x == float(‘nan’) doesn’t seem to work as expected. So what’s the correct and reliable way to check if a value is NaN in Python?

Would appreciate a clear explanation or example of how to handle this.