like and uand even chinesejapaneseand arabic symbols howevernot every system can display decorated charactersso it' good idea to avoid them if you're going to share your code with people in different regions note you'll learn more about unicode in you can also read about python' support for unicode in the official python documentation just because variable name is valid doesn' necessarily mean that it' good name choosing good name for variable can be surprisingly difficult fortunatelythere are some guidelines that you can follow to help you choose better names descriptive names are better than short names descriptive variable names are essentialespecially for complex programs writing descriptive names often requires using multiple words don' be afraid to use long variable names in the following examplethe value is assigned to the variable ss the name is totally ambiguous using full word makes it lot easier to understand what the code meansseconds