怎么用python查找屏幕上是否存在1234这四个字？

Install any library to do screenshot and save to image file, like pyautogui

import pyautogui
import easyocr

file = 'screen.jpg'
pyautogui.screenshot().save(file)

reader = easyocr.Reader(['ch_sim','en'])
result = reader.readtext(file, detail = 0)
print(result)

if any(map(lambda x:'1234' in x, result)):
    print('Yes, "1234" found !')
else:
    print('No, "1234" not found !')

It may depend on the platform you use.

Following code may work for Windows, other platform may need different code for them.

from PIL import ImageGrab
import win32gui

hwnd = win32gui.FindWindow(None, r'Window_Title')
win32gui.SetForegroundWindow(hwnd)
dimensions = win32gui.GetWindowRect(hwnd)

image = ImageGrab.grab(dimensions)
image.show()

可以尝试opencv的模版匹配