In Python, while true is a commonly used infinite loop statement that ensures that the block is executed an infinite number of times until a specific exit condition is met.
This article will provide a comprehensive introduction to the use of while true, including how it works, parameters, return values, and examples** to help readers better understand and apply this concept. Premium short** plan
Overview. While true is a loop control statement in Python that is used to implement infinite loops. true is a Boolean constant that means always true.
As a result, while true will execute its ** block an infinite number of times until a break statement is encountered or the program is manually terminated.
This type of loop is often used when a segment needs to be executed repeatedly, and as long as a certain condition is met, the loop will continue to be executed.
Here are some examples of using while true** to show how it can be used in different scenarios:
An infinite loop awaits user input.
while true: Loop (tab) user input = input("Please enter a number:")(tab)if user_input.isdigit():2tab)break(tab)print("If the input is invalid, please re-enter a number!")print("The number you enter is:", user_input)
In this example, while true is used to create an infinite loop waiting for the user to enter a number.
If the user enters a number, then the loop will pass"break"statement termination;Otherwise, the program will print an error message and continue to wait for user input.
Detect keystroke events in an infinite loop.
import keyboardwhile true:(tab)if keyboard.is_pressed('q'):(2tab)print("You pressed'q'key"(2tab)break (tab)print("Wait for the key press event. ")
In this example, while true is used to create an infinite loop that detects if the user presses it'q'key
If the user pressed'q'key, then the loop will pass"break"The statement terminates and a message is printed. Otherwise, the program will print a waiting message and continue waiting.
Send network requests in an infinite loop.
import timeimport requestswhile true: start of the loop (tab)try:(2tab)response = requests.get('')(2tab)response.Raise for status() throws an HTTPError exception if the request returns a status code other than 200. (2tab)print("The request was successful!"(2tab)break If the request is successful, the loop is terminated with a break statement. (tab)except requests.exceptions.requestexception as error:(2tab)print("Request failed!Error message:", error)(2tab)time.sleep(5) Wait 5 seconds and try the request again.
In this example,"while true"Used to create an infinite loop that continuously sends network requests. If the request is successful, then the loop will pass"break"statement termination;If the request fails, the program prints an error message and waits for 5 seconds before trying the request again.
Summary. It is important to note that while true needs to be used with caution, as it will cause the program to continue to execute until a specific exit condition is met.
Therefore, in practical applications, we should choose whether to use while true according to actual needs, and ensure that appropriate exit conditions are provided when using to avoid the program falling into an endless loop.