Python variables types
Python variables types
I'd be happy to help!
Python is a high-level programming language that has several built-in variable types, which can be categorized into two main groups: immutable and mutable.
Immutable Types:
Integers (int): These are whole numbers, either positive or negative.
Example: x = 5 is an integer variable with the value of 5.
float): These represent decimal numbers or floating-point numbers.
Example: y = 3.14 is a float variable with the value of 3.14.
bool): This represents a true or false value.
Example: z = True is a boolean variable that is set to true.
complex): These are complex numbers, which can be represented in the format a + bj, where a and b are real numbers, and j is the imaginary unit.
Mutable Types:
Strings (str): These represent sequences of characters or strings.
Example: name = "John" is a string variable that holds the value "John".
list): These can hold multiple values, which are ordered collections of elements.
Example: fruits = ["apple", "banana", "cherry"] is a list variable that contains three strings.
tuple): These are immutable ordered collections of elements, similar to lists but cannot be changed after creation.
Example: colors = ("red", "green", "blue") is a tuple variable that contains three strings.
dict): These represent mappings between keys and values, often used for storing data in a structured manner.
Example: person = {"name": "John", "age": 30} is a dictionary variable that stores name and age information.
Other Types:
Sets (set): These are unordered collections of unique elements.
Example: unique_numbers = {1, 2, 3, 4, 5} is a set variable that contains five integers.
None): This represents the absence or non-availability of an object.
Example: x = None sets the value of x to None.
In Python, you can assign values to variables using assignment statements (e.g., x = 5), and you can also use built-in functions such as print() or len() to interact with your variables.
Rules for naming variables in Python
I'm happy to respond in English this time! Here are the rules for naming variables in Python:
1. Letters and Underscores: Variable names can be composed of letters (a-z, A-Z), underscores (_), and digits (0-9). They must start with a letter or underscore.
2. No Special Characters: Avoid using special characters like !, @, #, $, %, etc., as they may not be recognized by Python.
3. Case Sensitivity: Python is case-sensitive, meaning that myVariable and MyVariable are treated as two different variables.
4. No Reserved Keywords: Avoid using reserved keywords in Python, such as if, for, while, def, etc., as variable names.
5. Consecutive Underscores: You can use consecutive underscores (e.g., _ _), but this is generally not recommended.
6. Single Underscore for Private Variables: In Python, single underscore (_) is a convention to indicate private variables or methods that should not be accessed directly from outside the class. This is known as "name mangling."
7. Descriptive Variable Names: Use descriptive variable names that indicate their purpose, making your code easier to understand and maintain.
Some best practices for naming variables in Python:
Be consistent: Choose a naming convention (e.g., camelCase or underscore notation) and stick to it throughout your codebase. Keep it short: Aim for variable names with 1-3 words that convey their meaning. Avoid duplication: Use unique variable names to avoid confusion and errors.Examples of good variable names in Python:
student_name total_score average_grade
Examples of bad variable names in Python:
x (too generic) __private_var (should use name mangling) aVariableNamedSomethingRandomAndUnhelpful
By following these rules and best practices, you can write readable, maintainable, and efficient Python code.
References:
Python Documentation: Variables W3Schools: Python Variables Real Python: Naming Conventions in Python
