A type of error. This is when the computer doesn’t know of any variable with that name. Usually this happens when you’ve misspelled a variable (even if the letters are correct – the capitalisation must be exact too), or haven’t declared it (stated what you’re going to put in it).
An error that is returned for variables that do not have a value. In Python, null values could be either because the code is expecting a number but the variable hasn’t stored it as such (NaN) or because the variable is not applicable (N/A) in this context for some reason. In other programming languages, a […] Read the full article Null value
A scientific calculations module for the Python programming language.