There are several rules for naming variables in Python. These are the following:
- A variable name must start with a letter or the underscore character, which means a variable name can not begin with a number.
- A variable name may contain only English letters, numbers, and underscore characters.
- Variables’ names are case sensitive, i.e., `Chapter`, `chapter`, and `CHAPTER` will be considered three different objects by Python.

Choose all the acceptable names for variables.

Python is an interpreted high-level, general-purpose programming language, which means it can be used in different spheres of human activity (unlike HTML, CSS, and JavaScript, which are mainly used in web development). Python can be used in software developing, data science, back-end development, etc. In this mobile-friendly version of the course, you will meet with the main aspects of Python.

In the first section, you will be introduced to the very basics of Python - how to interact with Python, perform simple operations, and output results.

In the past section, you performed different operations with numbers. In this section, you will learn how to save values in computer memory and be able to use them in the future for any purpose.

During the last two sections, you mostly worked with numerical data. In the third section, you will learn how to work with textual data in Python (strings), how to manipulate such data, what methods can be applied to them, and so on.

Naming Rules