Introduction to Python functions: functions and usage examples of globals functions

Introduction to Python functions: functions and usage examples of globals functions

Python is a powerful programming language that provides many built-in functions, among which the globals() function It's one of them. This article will introduce the functions and usage examples of the globals() function, with specific code examples.

1. Function of globals function

The globals() function is a built-in function used to return a dictionary of global variables of the current module. It returns a dictionary containing global variables, where the keys are the variable names and the values ​​are the values ​​of the variables.

Use the globals() function to access and operate global variables in the form of a dictionary. Within the function, if we want to obtain or modify global variables, we can use the globals() function to achieve this.

At the same time, the globals() function can also be used to inspect and debug code. By printing the returned dictionary, we can view all global variables of the current module and their corresponding values ​​to better understand the execution process of the code.

2. Examples of using the globals function

The following are some specific code examples showing the usage scenarios and functions of the globals() function.

1. Get global variables

Suppose we have a global variable x and want to access it inside a function. This can be achieved using the globals() function:

x = 10

def func():
    global_x = globals()['x']
    print(global_x)

func()  # 输出：10

In this example, we first define a global variable x and assign it a value of 10. Then, we define a function func(), use the globals() function inside the function to obtain the global variable x, and print it out. Run the func() function and the output result is 10.

2. Modify global variables

In addition to obtaining the value of global variables, the globals() function can also be used to modify global variables. We can access global variables through dictionaries and modify their values ​​through assignment.

x = 10

def modify_global():
    globals()['x'] = 20

modify_global()
print(x)  # 输出：20

In this example, we define the function modify_global(), use the globals() function inside the function to obtain the global variable x, and assign it a value of 20. Then, we print the value of the global variable x, and the output is 20.

3. Check global variables

In addition to using the globals() function to access and modify global variables inside the function, we can also use the globals() function to check all of the current module Global variables.

x = 10
y = 20
z = 30

def check_globals():
    global_vars = globals()
    for var in global_vars:
        print(var, global_vars[var])

check_globals()

In this example, we define three global variables x, y, and z and assign them different values. Then, we defined the function check_globals(), used the globals() function inside the function to obtain the dictionary of global variables, and printed each global variable and its corresponding value through a for loop. Run the check_globals() function, the output result is as follows:

x 10
y 20
z 30

By printing the returned dictionary, we can clearly see all the global variables of the current module and their corresponding values.

Summary:

This article introduces the functions and usage examples of the globals() function. Through the globals() function, we can obtain, modify and check the global variables of the current module, which improves the flexibility and readability of the code. Using the globals() function can more conveniently access and operate global variables to adapt to different programming needs.

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