Here is how to use global variables in a function in Python.

# Define a global variable
my_var = 10

# Define a function that uses the global variable
def my_function():
    # Declare the variable as global
    global my_var

    # Use the global variable
    my_var += 1

# Call the function
my_function()

# Print the global variable
print(my_var) 

Copy & Run

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To use a global variable in a function in Python, you must first declare the variable as global in the function using the global keyword.

It's important to note that using global variables can make your code difficult to read and maintain, and can also cause unexpected behaivor if the same global variable is modified by multiple functions. It's generally better to avoid using global variables whenever possible, and instead pass the necessary variables as arguments to the function.

Here's an example of how you can avoid using global variables by passing the necessary variables as arguments to the function:

# Define a variable
my_var = 10

# Define a function that uses the variable
def my_function(var):
    # Use the variable
    var += 1
    return var

# Call the function and pass the variable as an argument
my_var = my_function(my_var)

# Print the variable
print(my_var)

This will also print 11, but without using global variables.

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