Variables are used to store and manipulate data in a computer program. Think of them as named containers for different types of . Variables allow us to values and retrieve them later when needed. They help in simplifying the code and make it easier to understand and maintain. With variables, we can perform operations and calculations using the stored data. For example, we can declare a variable named "age" of the type , which is a whole number. Once a variable is declared, we can assign a value to it using the assignment operator (=). For example, to assign the value 16 to the "age" variable, we do: = 16; Now, the "age" variable holds the value 16.
When naming variables in Python, you need to follow certain rules. A variable name can only contain letters (a to z, A to Z), digits (0 to 9), and . It cannot start with a digit. Variable names are case-sensitive, which means variable and Variable are considered different. Spaces and special characters (such as !, @, #) are not allowed in variable names. In Python, there are a number of that cannot be used as a variable. If you try to use them, Python will raise a syntax error. Additionally, it is considered good practice to use sensible variable names that describe the purpose or content of the variable, improving code readability.
A constant is similar to a variable, except that its value remains unchanged throughout the program. It is typically used for values that are known and . In Python, constants are implemented using variables that are named using uppercase letters to indicate their immutability (unchangeability). For example, we might define a constant as = 3.14159. Here, PI is assigned the constant value of 3.14159. Note that Python treats constants and variables exactly the same; the use of UPPERCASE LETTERS convention helps make writing and maintaining programs easier.
Keywords
age | pi | underscores | integer | store | fixed | information | words |
