默认情况下， 性能日志是 禁用的 。
要启用它，请使用
DesiredCapabilities并配置
loggingPrefs：
from selenium import webdriverfrom selenium.webdriver.common.desired_capabilities import DesiredCapabilitiescaps = DesiredCapabilities.CHROME #as per latest docscaps['goog:loggingPrefs'] = {'performance': 'ALL'}driver = webdriver.Chrome(desired_capabilities=caps)driver.get('https://stackoverflow.com')for entry in driver.get_log('performance'): print(entry)driver.quit()这导致在控制台上打印了一堆跟踪日志条目：
{u'timestamp': 1419487459178, u'message': u'{"message":{"method":"Network.responseReceived","params":{"frameId":"2105.1","loaderId":"2105.2","requestId":"2105.1","response":{"connectionId":0,"connectionReused":false,"enpredDataLength":-1,"fromDiskCache":false,"fromServiceWorker":false,"headers":{"Access-Control-Allow-Origin":"*","Content-Type":"text/plain;charset=US-ASCII"},"mimeType":"text/plain","status":200,"statusText":"OK","url":"data:,"},"timestamp":1419487458.92934,"type":"document"}},"webview":"2C66E956-A48B-456B-8A4E-1022F699AA92"}', u'level': u'INFO'}{u'timestamp': 1419487459178, u'message': u'{"message":{"method":"Network.loadingFinished","params":{"enpredDataLength":0,"requestId":"2105.1","timestamp":1419487458.92936}},"webview":"2C66E956-A48B-456B-8A4E-1022F699AA92"}', u'level': u'INFO'}{u'timestamp': 1419487459178, u'message': u'{"message":{"method":"Page.frameNavigated","params":{"frame":{"id":"2105.1","loaderId":"2105.2","mimeType":"text/plain","securityOrigin":"://","url":"data:,"}}},"webview":"2C66E956-A48B-456B-8A4E-1022F699AA92"}', u'level': u'INFO'}...
