python实现屏幕截图

from selenium import webdriver
import time

def capture(url, save_fn="capture.png"):
    browser = webdriver.Firefox()  # Get local session of firefox
    browser.set_window_size(1200, 900)
    browser.get(url)  # Load page
    browser.execute_script("""
    (function () {
      var y = 0;
      var step = 100;
      window.scroll(0, 0);

      function f() {
        if (y < document.body.scrollHeight) {
          y += step;
          window.scroll(0, y);
          setTimeout(f, 50);
        } else {
          window.scroll(0, 0);
          document.title += "scroll-done";
        }
      }

      setTimeout(f, 1000);
    })();
  """)

    for i in xrange(30):
        if "scroll-done" in browser.title:
            break
        time.sleep(1)

    browser.save_screenshot(save_fn)
    browser.close()

if __name__ == "__main__":
    capture("http://www.jb51.net")