123

我想从python的键盘中读取数据

我尝试这样：

nb = input('Choose a number')
print ('Number%s \n' % (nb))

但是，无论是日食还是终端，它都不起作用，这始终是问题的解决之道。我可以输入数字，但是什么都没发生。

你知道为什么吗？

python input keyboard

— 特伦
source

12

我很确定OP只是在输入数字后忘记按回车键，而且没有答案能真正回答问题。

— 阿兰·菲

127

尝试

raw_input('Enter your input:')  # If you use Python 2
input('Enter your input:')      # If you use Python 3

如果您想要一个数值，只需将其转换为：

try:
    mode=int(raw_input('Input:'))
except ValueError:
    print "Not a number"

— 锐利的
source

2

非阻塞多线程版本，因此您可以继续做而不是阻塞键盘输入：stackoverflow.com/a/53344690/4561887

— Gabriel Staples

84

似乎您在这里混合使用不同的Python（Python 2.x与Python 3.x）...这基本上是正确的：

nb = input('Choose a number: ')

问题在于它仅在Python 3中受支持。正如@sharpner回答的那样，对于旧版本的Python（2.x），必须使用以下函数raw_input：

nb = raw_input('Choose a number: ')

如果要将其转换为数字，则应尝试：

number = int(nb)

...尽管您需要考虑到这可能引发异常：

try:
    number = int(nb)
except ValueError:
    print("Invalid number")

如果要使用格式打印数字，str.format()建议在Python 3 中进行：

print("Number: {0}\n".format(number))

代替：

print('Number %s \n' % (nb))

但是两个选项（str.format()和%）在Python 2.7和Python 3中都可以使用。

— 巴尔塔萨克
source

1

space如果和平，请务必在用户输入的字符串后加上一个后缀，以供用户输入其输入内容。Enter Tel12340404VS Enter Tel: 12340404。看到！：P

— 梅拉德，2014年

做完了谢谢你的建议。

— 2014年

15

非阻塞，多线程示例：

由于阻塞键盘输入（由于input()功能块）通常不是我们想要做的（我们经常想继续做其他事情），所以这是一个精简的多线程示例以演示如何保持运行。主要应用程序，同时还在到达时仍在读取键盘输入。

通过创建一个在后台运行的线程，不断调用input()，然后将接收到的所有数据传递到队列中，可以实现这一目的。

这样，您的主线程就可以做任何想做的事情，只要队列中有东西，它就会从第一个线程接收键盘输入数据。

1.裸Python 3代码示例（无注释）：

import threading
import queue
import time

def read_kbd_input(inputQueue):
    print('Ready for keyboard input:')
    while (True):
        input_str = input()
        inputQueue.put(input_str)

def main():
    EXIT_COMMAND = "exit"
    inputQueue = queue.Queue()

    inputThread = threading.Thread(target=read_kbd_input, args=(inputQueue,), daemon=True)
    inputThread.start()

    while (True):
        if (inputQueue.qsize() > 0):
            input_str = inputQueue.get()
            print("input_str = {}".format(input_str))

            if (input_str == EXIT_COMMAND):
                print("Exiting serial terminal.")
                break

            # Insert your code here to do whatever you want with the input_str.

        # The rest of your program goes here.

        time.sleep(0.01) 
    print("End.")

if (__name__ == '__main__'): 
    main()

2.与上述相同的Python 3代码，但带有大量说明性注释：

"""
read_keyboard_input.py

Gabriel Staples
www.ElectricRCAircraftGuy.com
14 Nov. 2018

References:
- https://pyserial.readthedocs.io/en/latest/pyserial_api.html
- *****https://www.tutorialspoint.com/python/python_multithreading.htm
- *****https://en.wikibooks.org/wiki/Python_Programming/Threading
- /programming/1607612/python-how-do-i-make-a-subclass-from-a-superclass
- https://docs.python.org/3/library/queue.html
- https://docs.python.org/3.7/library/threading.html

To install PySerial: `sudo python3 -m pip install pyserial`

To run this program: `python3 this_filename.py`

"""

import threading
import queue
import time

def read_kbd_input(inputQueue):
    print('Ready for keyboard input:')
    while (True):
        # Receive keyboard input from user.
        input_str = input()

        # Enqueue this input string.
        # Note: Lock not required here since we are only calling a single Queue method, not a sequence of them 
        # which would otherwise need to be treated as one atomic operation.
        inputQueue.put(input_str)

def main():

    EXIT_COMMAND = "exit" # Command to exit this program

    # The following threading lock is required only if you need to enforce atomic access to a chunk of multiple queue
    # method calls in a row.  Use this if you have such a need, as follows:
    # 1. Pass queueLock as an input parameter to whichever function requires it.
    # 2. Call queueLock.acquire() to obtain the lock.
    # 3. Do your series of queue calls which need to be treated as one big atomic operation, such as calling
    # inputQueue.qsize(), followed by inputQueue.put(), for example.
    # 4. Call queueLock.release() to release the lock.
    # queueLock = threading.Lock() 

    #Keyboard input queue to pass data from the thread reading the keyboard inputs to the main thread.
    inputQueue = queue.Queue()

    # Create & start a thread to read keyboard inputs.
    # Set daemon to True to auto-kill this thread when all other non-daemonic threads are exited. This is desired since
    # this thread has no cleanup to do, which would otherwise require a more graceful approach to clean up then exit.
    inputThread = threading.Thread(target=read_kbd_input, args=(inputQueue,), daemon=True)
    inputThread.start()

    # Main loop
    while (True):

        # Read keyboard inputs
        # Note: if this queue were being read in multiple places we would need to use the queueLock above to ensure
        # multi-method-call atomic access. Since this is the only place we are removing from the queue, however, in this
        # example program, no locks are required.
        if (inputQueue.qsize() > 0):
            input_str = inputQueue.get()
            print("input_str = {}".format(input_str))

            if (input_str == EXIT_COMMAND):
                print("Exiting serial terminal.")
                break # exit the while loop

            # Insert your code here to do whatever you want with the input_str.

        # The rest of your program goes here.

        # Sleep for a short time to prevent this thread from sucking up all of your CPU resources on your PC.
        time.sleep(0.01) 

    print("End.")

# If you run this Python file directly (ex: via `python3 this_filename.py`), do the following:
if (__name__ == '__main__'): 
    main()

样本输出：

$ python3 read_keyboard_input.py
准备好进行键盘输入：
嘿
input_str =嘿
你好
input_str =你好
7000
input_str = 7000
exit
input_str = exit
退出串行终端。
结束。

如何阅读键盘输入？

非阻塞，多线程示例：

1.裸Python 3代码示例（无注释）：

2.与上述相同的Python 3代码，但带有大量说明性注释：

样本输出：

参考文献：

相关/交叉链接：