Sys stdin readlines python как закончить ввод

How to finish sys.stdin.readlines() input in Python?

In Python, sys.stdin.readlines() is a method used to read all lines of input from the standard input device (e.g. keyboard). When used in a script or in the interactive shell, this method blocks execution until the user enters an end-of-file (EOF) character to indicate the end of input. The EOF character is typically Ctrl+D on Unix-based systems, or Ctrl+Z on Windows. However, some users may encounter issues when attempting to finish the input and close the input stream, particularly when working with large input data sets or in certain environments. In this article, we will explore several methods for finishing sys.stdin.readlines() input and closing the input stream in Python.

Method 1: Keyboard Interrupt

To finish sys.stdin.readlines() input in Python using Keyboard Interrupt, you can use the following code:

1. Import the sys module to use the stdin function.
2. Use a try-except block to capture the input from stdin using the readlines() method.
3. If the input is interrupted by the keyboard, the KeyboardInterrupt exception will be raised and the code inside the except block will be executed.
4. In this case, the code inside the except block will simply print a message to indicate that the input was interrupted by the keyboard.

Suppose you want to read multiple lines of input from the user until they type "quit". You can modify the above code as follows:

1. Use a while loop to repeatedly read input from the user using the input() function.
2. Check if the input is equal to "quit" using the strip() method to remove any leading or trailing whitespace.
3. If the input is "quit", break out of the loop.
4. If the input is interrupted by the keyboard, the KeyboardInterrupt exception will be raised and the code inside the except block will be executed.
5. In this case, the code inside the except block will simply print a message to indicate that the input was interrupted by the keyboard.

Suppose you want to read multiple lines of input from a file until the end of the file is reached or the input is interrupted by the keyboard. You can modify the above code as follows:

1. Use a for loop to iterate over each line of input from stdin .
2. Check if the input is an empty string using the strip() method to remove any leading or trailing whitespace.
3. If the input is an empty string, break out of the loop.
4. Print the input using the print() function after removing any leading or trailing whitespace using the strip() method.
5. If the input is interrupted by the keyboard, the KeyboardInterrupt exception will be raised and the code inside the except block will be executed.
6. In this case, the code inside the except block will simply print a message to indicate that the input was interrupted by the keyboard.

Method 2: End-of-File Character

To finish input with sys.stdin.readlines() in Python using the "End-of-File Character", you can follow these steps:

1. Import the sys module.

1. Use the readlines() function of the sys.stdin object to read input from the user.

To indicate the end of input, press Ctrl + D on Linux or Ctrl + Z on Windows. This will send the "End-of-File Character" to the program.

You can then process the input as required.

Here is an example code snippet that demonstrates the above steps:

When you run this code, you can enter multiple lines of input. To indicate the end of input, press Ctrl + D on Linux or Ctrl + Z on Windows. The program will then process the input and display it on the console.

Here is another example that uses a while loop to read input until the "End-of-File Character" is received:

This code reads input from the user using the input() function in a loop until the "End-of-File Character" is received. The input is then processed and displayed on the console.

Note that the second example can also be used with sys.stdin by replacing input() with sys.stdin.readline() .

Method 3: KeyboardTimeoutExpired Error

To finish sys.stdin.readlines() input with a KeyboardTimeoutExpired error, you can use the select module to set a timeout on sys.stdin and catch the KeyboardInterrupt exception. Here is an example:

In this example, the read_input function reads input from sys.stdin with a timeout of 5 seconds. If input is received within the timeout, it is added to a list of input lines. If no input is received within the timeout, a KeyboardInterrupt exception is raised.

The try block calls the read_input function and prints the list of input lines if input is received before the timeout. If a KeyboardInterrupt exception is caught, it prints a message indicating that the timeout has expired.

How to finish sys.stdin.readlines() input?

This might be a silly question, but as I can’t find an answer, I have to ask it.

In interactive python I want to process a message which i get with:

Everything works fine, but. how to stop it from getting an input and make it save into message variable? Stopping with ctrl+c stops whole process so there is no input to be saved anywhere. I guess there’s an easy answer I just can’t find.

6 Answers 6

For UNIX based systems (Linux, Mac):

Hello, you can type : Ctrl d

Ctrl d closes the standard input (stdin) by sending EOF.

For Windows :

To send EOF on Windows, type Ctrl z

This is an old question but it needs an update about Windows and different keyboard layouts.

If neither CTRL + Z nor CTRL + D ** work for you on Windows and and you’re wandering what is going on do this:

• check if you are using default english keyboard layout
• if you do have different, non-default keyboard layout try switching keyboard setting to English in language bar, then try pressing ctrl + z after changes
• if you’re still confused look at the screen, what appears in command line when you press ctrl + z. What symbol do you see? When I was pressing ctrl + z I was seeing this: ^Y, and when by mistake I pressed ctrl + y I’ve seen this ^Z, i pressed enter and the input was taken, EOF sent.

This is somewhat strange and counterintuitive. I changed keys layout some time ago to include polish characters, but all the common keys are left unchanged, z still maps to z when I use the keyboard normally, normally ctrl + z does nothing in my keyboard, so I shouldn’t be changed. But apparently in cmd it works differently, in order to have default link between ctrl and z I have to switch to default layout, or use control y to sent EOF.

How to finish sys.stdin.readlines() input?

Ctrl d closes the standard input (stdin) by sending EOF.

For Windows :

To send EOF on Windows, you can replace Ctrl d by Ctrl z

Solution 2

On windows simply do CTRL+Z and press enter

Solution 3

If you are a Mac user, please use command + D. It works!

Gandi

Updated on February 21, 2021

Comments

This might be a silly question, but as I can’t find an answer, I have to ask it.

In interactive python I want to process a message which i get with:

Everything works fine, but. how to stop it from getting an input and make it save into message variable? Stopping with ctrl+c stops whole process so there is no input to be saved anywhere. I guess there’s an easy answer I just can’t find.

Как завершить ввод sys.stdin.readlines ()?

Это может быть глупый вопрос, но, поскольку я не могу найти ответа, я должен его задать.

В интерактивном питоне я хочу обработать сообщение, которое я получаю:

Все работает нормально, но . как не дать ему получить ввод и сохранить его в переменной сообщения? Остановка с помощью ctrl + c останавливает весь процесс, поэтому никаких данных для сохранения нигде не требуется. Думаю, есть простой ответ, который я просто не могу найти .

5 ответы

Для системы на основе unix:

Здравствуйте, можете записать: Ctrl d

Ctrl d закрывает стандартный ввод (stdin), отправляя EOF.

Для Windows:

Чтобы отправить EOF в Windows, вы можете заменить Ctrl d by Ctrl z

ответ дан 05 апр.

Это старый вопрос, но он нуждается в обновлении о Окна и разные раскладки клавиатуры.

Если ни CTRL+Z ни CTRL + D ** работает для вас в Windows и вы блуждаетесь, что происходит, сделайте это:

• проверьте, используете ли вы английская раскладка клавиатуры по умолчанию
• если у вас другая, нестандартная раскладка клавиатуры, попробуйте переключить настройку клавиатуры на английский на языковой панели, а затем попробуйте нажать ctrl + z после изменений
• если вы все еще не уверены, посмотрите на экран, что появляется в командной строке при нажатии ctrl + z. Какой символ вы видите? Когда я нажимал ctrl + z, я видел это: ^ Y, и когда я по ошибке нажал ctrl + y, я увидел это ^ Z, я нажал Enter, и ввод был принят, EOF отправлен.

Это несколько странно и нелогично. Некоторое время назад я изменил раскладку клавиш, чтобы включить полированные символы, но все общие клавиши остались без изменений, z по-прежнему сопоставляется с z, когда я обычно использую клавиатуру, обычно ctrl + z ничего не делает на моей клавиатуре, поэтому меня не следует менять . Но, по-видимому, в cmd он работает по-другому, чтобы иметь связь по умолчанию между ctrl и z, мне нужно переключиться на макет по умолчанию или использовать элемент управления y для отправки EOF.