In this article, you will learn the basics of global variables. To begin with, you will learn how to declare variables in Python and what the term 'variable scope' actually means. Then, you will learn the differences between local and global variables and understand how to define global variables and how to use the Here is what we will cover: You can think of variables as storage containers. They are storage containers for holding data, information, and values that you would like to save in the computer's memory. You can then reference or even manipulate them at some point throughout the life of the program. A variable has a symbolic name, and you can think of that name as the label on the storage container that acts as its identifier. The variable name will
be a reference and pointer to the data stored inside it. So, there is no need to remember the details of your data and information – you only need to reference the variable name that holds that data and information. When giving a variable a name, make sure that it is descriptive of the data it holds. Variable names need to be clear and easily understandable both for your future self and the other developers you may be working with. Now, let's see how to actually create a variable in
Python. When declaring variables in Python, you don't need to specify their data type. For example, in the C programming language, you have to mention explicitly the type of data the variable will hold. So, if you wanted to store your age which is an integer, or
However, this is how you would write the above in Python:
The variable name is always on the left-hand side, and the value you want to assign goes on the right-hand side after the assignment operator. Keep in mind that you can change the values of variables throughout the life of a program:
You keep the same variable name, What Does Variable Scope in Python Mean?Variable scope refers to the parts and boundaries of a Python program where a variable is available, accessible, and visible. There are four types of scope for Python variables, which are also known as the LEGB rule:
For the rest of this article, you will focus on learning about creating variables with global scope, and you will understand the difference between the local and global variable scopes. How to Create Variables With Local Scope in PythonVariables defined inside a function's body have local scope, which means they are accessible only within that particular function. In other words, they are 'local' to that function. You can only access a local variable by calling the function.
Look at what happens when I try to access that variable with a local scope from outside the function's body:
It raises a How to Create Variables With Global Scope in PythonWhen you define a variable outside a function, like at the top of the file, it has a global scope and it is known as a global variable. A global variable is accessed from anywhere in the program. You can use it inside a function's body, as well as access it from outside a function:
What happens when there is a global and local variable, and they both have the same name?
In the example above, maybe you were not expecting that specific output. Maybe you thought that the value of Maybe you expected that when I referenced the
global variable with the line However, when the function was called, it printed the value of the local variable. Then, when I referenced the global variable outside the function, the value assigned to the global variable was printed. They didn't interfere with one another. That said, using the same variable name for global and local variables is not considered a best practice. Make sure that your variables don't have the same name, as you may get some confusing results when you run your program. How to Use the global Keyword in PythonWhat if you have a global variable but want to change its value inside a function? Look at what happens when I try to do that:
By default Python thinks you want to use a local variable inside a function. So, when I first try to print the value of the variable and then re-assign a value to the variable I am trying to access, Python gets confused. The way to change the value of a global variable inside a function is by using the
Use the Earlier, you saw that you couldn't access variables created inside functions since they have local scope. The
ConclusionAnd there you have it! You now know the basics of global variables in Python and can tell the differences between local and global variables. I hope you found this article useful. To learn more about the Python programming language, check out freeCodeCamp's Scientific Computing with Python Certification. You'll start from the basics and learn in an interactive and beginner-friendly way. You'll also build five projects at the end to put into practice and help reinforce what you've learned. Thanks for reading and happy coding! Learn to code for free. freeCodeCamp's open source curriculum has helped more than 40,000 people get jobs as developers. Get started How can you access a global variable inside the function if function has a variable with same name Python?To access a global variable in a function, if the function has a local variable with the same name, we use the global keyword before the variable name.
How do you access a global variable inside the function if function has a variable with the same name explain with example?If your function has a local variable with same name as global variable and you want to modify the global variable inside function then use 'global' keyword before the variable name at start of function i.e. As you can see modification done to global variable total is now visible outside the function too.
How can you access a global variable inside the function?Rules of global Keyword. When we create a variable inside a function, it is local by default.. When we define a variable outside of a function, it is global by default. ... . We use global keyword to read and write a global variable inside a function.. Use of global keyword outside a function has no effect.. How do you access global variable if there is a local variable with same name in Python?It is also possible to use a global and local variable with the same name simultaneously. Built-in function globals() returns a dictionary object of all global variables and their respective values. Using the name of the variable as a key, its value can be accessed and modified.
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