Python – Global Variables

In Python, global variables are variables that are defined outside of any function or class. These variables can be accessed and modified from any part of the code. In this blog post, we’ll explore the concept of global variables, their usage, and best practices.

What are Global Variables?

Global variables are variables that are declared at the top level of a Python script or module. They are not bound to any specific function or class and can be accessed from any part of the code. However, there are some important considerations when using global variables.

Usage of Global Variables

  1. Declaring Global Variables: To declare a global variable, simply assign a value to it outside of any function or class. For example:
    global_var = 42
  2. Accessing Global Variables: You can access global variables from within functions or methods. However, you need to use the global keyword to indicate that you are referring to the global variable. For instance:
    def print_global_var():
        global global_var
        print(f"The global variable value is: {global_var}")
  3. Modifying Global Variables: To modify a global variable within a function, use the global keyword and then assign a new value to it. For example:
    def modify_global_var():
        global global_var
        global_var = 100
  4. Best Practices:
    • Use global variables sparingly. They can make code harder to understand and maintain.
    • Avoid modifying global variables from multiple places in your code to prevent unexpected behavior.
    • Consider using function arguments or class attributes instead of global variables whenever possible.

Understanding global variables is essential for writing clean and maintainable Python code. By following best practices and being mindful of their usage, you can harness the power of global variables effectively.

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