谈谈Selenium中的日志

来源于一位同学，“老师为啥firefox执行后会有日志文件，chrome没有呢？”

比对

你打开chrome浏览器

from selenium import webdriver

driver = webdriver.Chrome()

这样是没有日志的

同样的代码，你打开firefox

from selenium import webdriver

driver = webdriver.Firefox()

就会有个日志文件geckodriver.log生成，默认在你上面代码所在目录

内容大致如下

1678943199197	geckodriver	INFO	Listening on 127.0.0.1:8695

1678943202290	mozrunner::runner	INFO	Running command: "C:\\Program Files\\Mozilla Firefox\\firefox.exe" "--marionette" "--remote-debugging-port" "8696" "-no-remote" "-profile" "C:\\Users\\SONGQI~1\\AppData\\Local\\Temp\\rust_mozprofileNtWGR9"

1678943202558	Marionette	INFO	Marionette enabled

Dynamically enable window occlusion 0

1678943202562	Marionette	INFO	Listening on port 8705

WebDriver BiDi listening on ws://127.0.0.1:8696

1678943202947	RemoteAgent	WARN	TLS certificate errors will be ignored for this session

console.warn: SearchSettings: "get: No settings file exists, new profile?" (new NotFoundError("Could not open the file at C:\\Users\\SONGQI~1\\AppData\\Local\\Temp\\rust_mozprofileNtWGR9\\search.json.mozlz4", (void 0)))

DevTools listening on ws://127.0.0.1:8696/devtools/browser/791df03a-8db6-429b-969a-32cd077b3c2f

的确是这样的，chrome和firefox2个浏览器在selenium中的api都是有差异的

下面的代码可以让你看到2者独有的那些api

from selenium import webdriver

driver1 = webdriver.Chrome()

driver2 = webdriver.Firefox()

set_of_chrome_api = set([_ for _ in dir(driver1) if _[0]!='_'])

set_of_firefox_api = set([_ for _ in dir(driver2) if _[0]!='_'])

print('firefox特有的:',(set_of_chrome_api|set_of_firefox_api)-set_of_chrome_api)

print('-------------')

print('chrome特有的:',(set_of_chrome_api|set_of_firefox_api)-set_of_firefox_api)

让chrome也有日志

首先来看下Chrome这个类的初始化参数都有哪些

# selenium\webdriver\chrome\webdriver.py

class WebDriver(ChromiumDriver):

    def __init__(self, executable_path=DEFAULT_EXECUTABLE_PATH, port=DEFAULT_PORT,

                 options: Options = None, service_args=None,

                 desired_capabilities=None, service_log_path=DEFAULT_SERVICE_LOG_PATH,

                 chrome_options=None, service: Service = None, keep_alive=DEFAULT_KEEP_ALIVE):

你应该一眼就看到有日志相关的参数了service_log_path

有个默认值DEFAULT_SERVICE_LOG_PATH

往上能看到定义：DEFAULT_SERVICE_LOG_PATH = None

所以chrome就没有日志了

要有就简单了，给一个值就行了，这样

from selenium import webdriver

driver = webdriver.Chrome(service_log_path='chrome.log')

妥妥的在当前目录下生成了一个chrome.log文件里面也记录着本次操作的日志

多说几句，默认的日志就记录到INFO/WARN这样的级别

如果要加DEBUG的信息，可以这样

from selenium import webdriver

driver = webdriver.Chrome(service_args=['--verbose'],

                          service_log_path='chrome.log')

让firefox没有日志，没那么简单

循着刚才的思路，让firefox没有日志似乎就很简单了

依葫芦画瓢，找到Firefox的定义

# selenium\webdriver\firefox\webdriver.py

# 注意，此处的路径跟上面的chrome的并不一样

class WebDriver(RemoteWebDriver):

    def __init__(self, firefox_profile=None, firefox_binary=None,

                 capabilities=None, proxy=None,

                 executable_path=DEFAULT_EXECUTABLE_PATH, options=None,

                 service_log_path=DEFAULT_SERVICE_LOG_PATH,

                 service_args=None, service=None, desired_capabilities=None,

                 log_path=DEFAULT_LOG_PATH, keep_alive=True):

看到了参数service_log_path，一样也有默认值DEFAULT_SERVICE_LOG_PATH

找到定义处，DEFAULT_SERVICE_LOG_PATH = "geckodriver.log"

改为None试试

from selenium import webdriver

driver = webdriver.Firefox(service_log_path=None)

效果有，但又有点不对

控制台冒出了很多信息

demo_log.py:2: DeprecationWarning: service_log_path has been deprecated, please pass in a Service object

  driver = webdriver.Firefox(service_log_path=None)

1678944678241	geckodriver	INFO	Listening on 127.0.0.1:10729

1678944681310	mozrunner::runner	INFO	Running command: "C:\\Program Files\\Mozilla Firefox\\firefox.exe" "--marionette" "--remote-debugging-port" "10730" "-no-remote" "-profile" "C:\\Users\\SONGQI~1\\AppData\\Local\\Temp\\rust_mozprofileeEN3y9"

Dynamically enable window occlusion 0

1678944681583	Marionette	INFO	Marionette enabled

1678944681587	Marionette	INFO	Listening on port 10743

WebDriver BiDi listening on ws://127.0.0.1:10730

1678944681883	RemoteAgent	WARN	TLS certificate errors will be ignored for this session

console.warn: SearchSettings: "get: No settings file exists, new profile?" (new NotFoundError("Could not open the file at C:\\Users\\SONGQI~1\\AppData\\Local\\Temp\\rust_mozprofileeEN3y9\\search.json.mozlz4", (void 0)))

DevTools listening on ws://127.0.0.1:10730/devtools/browser/a4f3a501-e642-4540-8998-ae1ea0b3abc5

仔细一看，跟之前在geckodriver.log中打印的类似

还多了一句

DeprecationWarning: service_log_path has been deprecated, please pass in a Service object

原来service_log_path被弃用了，需要传递一个Service对象

怎么传递Service对象呢？找到其定义，注意路径

有多个Service在selenium这个库中，你要的是firefox下的

#  selenium\webdriver\firefox\service.py

class Service(service.Service):

    """Object that manages the starting and stopping of the

    GeckoDriver."""

    def __init__(self, executable_path: str = DEFAULT_EXECUTABLE_PATH,

                 port: int = 0, service_args: List[str] = None,

                 log_path: str = "geckodriver.log", env: dict = None):

可以看到，这里有个参数log_path，其默认值是"geckodriver.log"

那我们就可以这样修改了

from selenium import webdriver

from selenium.webdriver.firefox.service import Service

# 听你的，传递一个Service对象

# Service(log_path='') 就是一个

driver = webdriver.Firefox(service=Service(log_path=''))

至此DeprecationWarning: service_log_path has been deprecated, please pass in a Service object的这段没了

不过下面的1678945260755 geckodriver INFO Listening on 127.0.0.1:11634，这样的仍然存在的

而这部分实际是geckodriver这个驱动的打印信息

C:\Users\xxx>geckodriver

1678945567307   geckodriver     INFO    Listening on 127.0.0.1:4444

如果要去掉，就是让geckodriver这个程序静默

没有找到太好的办法，geckodriver的帮助如下

C:\Users\xxx>geckodriver --help

geckodriver 0.30.0 (d372710b98a6 2021-09-16 10:29 +0300)

WebDriver implementation for Firefox

USAGE:

    geckodriver [FLAGS] [OPTIONS]

FLAGS:

        --connect-existing    Connect to an existing Firefox instance

    -h, --help                Prints this message

        --jsdebugger          Attach browser toolbox debugger for Firefox

    -v                        Log level verbosity (-v for debug and -vv for trace level)

    -V, --version             Prints version and copying information

OPTIONS:

        --android-storage <ANDROID_STORAGE>    Selects storage location to be used for test data (deprecated). [possible

                                               values: auto, app, internal, sdcard]

    -b, --binary <BINARY>                      Path to the Firefox binary

        --log <LEVEL>                          Set Gecko log level [possible values: fatal, error, warn, info, config,

                                               debug, trace]

        --marionette-host <HOST>               Host to use to connect to Gecko [default: 127.0.0.1]

        --marionette-port <PORT>               Port to use to connect to Gecko [default: system-allocated port]

        --host <HOST>                          Host IP to use for WebDriver server [default: 127.0.0.1]

    -p, --port <PORT>                          Port to use for WebDriver server [default: 4444]

        --websocket-port <PORT>                Port to use to connect to WebDriver BiDi [default: 9222]

--log 这个参数可以让它控制输出级别

最终我们可以这样写

from selenium import webdriver

from selenium.webdriver.firefox.service import Service

driver = webdriver.Firefox(service=Service(log_path='',

                    service_args=['--log','fatal']))  # 你不能 ['--log fatal'] 会报错

然，即便如此，控制台一样有打印

Dynamically enable window occlusion 0

WebDriver BiDi listening on ws://127.0.0.1:12166

console.warn: SearchSettings: "get: No settings file exists, new profile?" (new NotFoundError("Could not open the file at C:\\Users\\SONGQI~1\\AppData\\Local\\Temp\\rust_mozprofiledrxhm5\\search.json.mozlz4", (void 0)))

DevTools listening on ws://127.0.0.1:12166/devtools/browser/22a37523-84bc-4bd6-a5e9-79c30825d1e8

啊~~~~~~~~~无语了，不弄了，放弃了，干点有意义的事情吧，有点无趣

谈谈Selenium中的日志的相关教程结束。