Python屏幕截图

问题描述

我正在尝试编写一个使用全局热键进行屏幕捕捉的程序。下面是相应的代码：

from datetime import datetime
import os
from pynput import keyboard
import pyautogui
import pathlib

def on_activate():
    today = datetime.Now()
    d = today.strftime("%Y-%m-%d-%H-%M-%s")
    myScreenshot = pyautogui.screenshot(region=(200,200,1720,800))
    time_stamp = '{:%y%d%m}'.format(today)
    fpath = pathlib.Path("C:","Users","Desktop","TestScreenCap",time_stamp)
    if not os.path.exists(fpath):
        os.makedirs(fpath)
    myScreenshot.save(pathlib.Path(fpath,d,".jpg"))

def for_canonical(f):
    return lambda k: f(l.canonical(k))

hotkey = keyboard.HotKey(
    keyboard.HotKey.parse('<ctrl>+<alt>+h'),on_activate)
with keyboard.Listener(
        on_press=for_canonical(hotkey.press),on_release=for_canonical(hotkey.release)) as l:
    l.join()

错误消息：

Unhandled exception in listener callback
Traceback (most recent call last):
  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\PIL\Image.py",line 2138,in save format = EXTENSION[ext]
KeyError: ''

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\pynput\_util\__init__.py",line 211,in inner
    return f(self,*args,**kwargs)
  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\pynput\keyboard\_win32.py",line 280,in _process self.on_press(key)
  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\pynput\_util\__init__.py",line 127,in inner
    if f(*args) is False:
  File "C:/Users/PycharmProjects/untitled1/123.py",line 18,in <lambda>
    return lambda k: f(l.canonical(k))
  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\pynput\keyboard\__init__.py",line 182,in press
    self._on_activate()
  File "C:/Users/PycharmProjects/untitled1/123.py",line 15,in on_activate
    myScreenshot.save(pathlib.Path(fpath,".jpg"))
  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\PIL\Image.py",line 2140,in save
    raise ValueError("unkNown file extension: {}".format(ext)) from e
ValueError: unkNown file extension: 
Traceback (most recent call last):
  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\PIL\Image.py",in save
    format = EXTENSION[ext]
KeyError: ''

上述异常是以下异常的直接原因：

Traceback (most recent call last):
  File "C:/Users/PycharmProjects/untitled1/123.py",line 26,in <module>
    l.join()

  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\pynput\_util\__init__.py",line 259,in join
    six.reraise(exc_type,exc_value,exc_traceback)

  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\six.py",line 702,in reraise
    raise value.with_traceback(tb)
  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\pynput\_util\__init__.py",in _process
    self.on_press(key)
  File "C:\Users\PycharmProjects\untitled1\venv\lib\site-packages\pynput\_util\__init__.py",in save
    raise ValueError("unkNown file extension: {}".format(ext)) from e
ValueError: unkNown file extension:

我不知道如何将图像保存到文件夹。我希望下面的代码行不通：

myScreenshot.save(pathlib.Path(fpath,".jpg"))

通过简单的操作将函数更改为on_activate，

Print("Hello")

热键脚本运行完美。

我是编程的新手，所以我们将不胜感激！

解决方法

这里是固定代码：

from datetime import datetime
import os
from pynput import keyboard
import pyautogui
import pathlib

def on_activate():
    today = datetime.now()
    d = today.strftime("%Y-%m-%d-%H-%M-%S")
    myScreenshot = pyautogui.screenshot(region=(200,200,1720,800))
    time_stamp = '{:%y%d%m}'.format(today)
    fpath = pathlib.Path("C:\\","Users","Desktop","TestScreenCap",time_stamp)
    if not os.path.exists(fpath):
        os.makedirs(fpath)
    myScreenshot.save(pathlib.Path(fpath,d + ".jpg"))

def for_canonical(f):
    return lambda k: f(l.canonical(k))

hotkey = keyboard.HotKey(
    keyboard.HotKey.parse('<ctrl>+<alt>+h'),on_activate)
with keyboard.Listener(
        on_press=for_canonical(hotkey.press),on_release=for_canonical(hotkey.release)) as l:
    l.join()

问题是您正在使用：

myScreenshot.save(pathlib.Path(fpath,d,".jpg"))

函数pathlib.Path(fpath,".jpg")将字符串添加到\的末尾，因此您尝试保存文件的路径为：

C:Users\Desktop\TestScreenCap\200309\2020-09-03-16-50-20\.jpg

如您所见，文件名是扩展名，会引发异常。

只需替换为：myScreenshot.save(pathlib.Path(fpath,d + ".jpg"))

指定路径上的另一个问题是C:被解释为Drive，因此在保存函数时，该路径将保存到程序当前正在运行的路径，而不是实际的指定路径。要修复此部分，只需将C:替换为C:\\。

阅读代码，我认为您希望将屏幕快照保存在当前用户桌面中，如果是这样，请将行fpath = pathlib.Path("C:\\",time_stamp)替换为fpath = pathlib.Path(os.path.join(os.path.join(os.environ['USERPROFILE']),'Desktop'),time_stamp)，然后在顶部添加import os 。这样，您就不必关心路径的正确生成。

pyautogui python