Python+selenium第一个测试案例

1、安装Python35
官网：https://www.python.org/downloads/windows/
我安装的版本是v3.5.2，Windows系统
安装过程中记得勾选安装到环境的复选框：Add Python 3.5 to PATH，不然安装完成后还需要手动进行环境变量的配置。



2、下载selenium插件
在cmd中输入命令：python-m pip install selenium
*如果提示Python不是内部或外部命令，就需要将Python路径配置到环境变量去
3、新建一个txt文件，取名并修改后缀为test.py，将以下代码复制并保存：
from selenium import webdriver
import time
browser = webdriver.Firefox()
browser.get("http://www.baidu.com")
time.sleep(5)
browser.close()4、执行Python文件
可直接双击test.py执行，更靠谱的方式还是在cmd中输入命令：python test.py
使用Firefox
如果这是第一次使用selenium，可能会报以下这个错误：
E:\python\selenium>python test.py
Traceback (most recent call last):
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\common\service.py", line 74, in start
stdout=self.log_file, stderr=self.log_file)
File "C:\Users\Python\Python35\lib\subproce
ss.py", line 947, in __init__
restore_signals, start_new_session)
File "C:\Users\Python\Python35\lib\subproce
ss.py", line 1224, in _execute_child
startupinfo)
FileNotFoundError: [WinError 2] The system cannot find the file specified

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "test.py", line 6, in <module>
browser = webdriver.Firefox() # Get local session of firefox
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\firefox\webdriver.py", line 142, in __init__
self.service.start()
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\common\service.py", line 81, in start
os.path.basename(self.path), self.start_error_message)
selenium.common.exceptions.WebDriverException: Message: 'geckodriver' executable
needs to be in PATH.

最后一行错误信息提示缺少geckodriver，从网上查找的解决方法看，需要手动下载该文件
官网：https://github.com/mozilla/geckodriver/releases
并将解压出来的geckodriver.exe放到Python的目录下，C:\Users\Python\Python35\
重新执行Python：python test.py
这时仍旧报错，但是错误信息换了一个：
Traceback (most recent call last):
File "test.py", line 8, in <module>
browser = webdriver.Firefox() # Get local session of firefox
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\firefox\webdriver.py", line 152, in __init__
keep_alive=True)
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\remote\webdriver.py", line 98, in __init__
self.start_session(desired_capabilities, browser_profile)
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\remote\webdriver.py", line 188, in start_session
response = self.execute(Command.NEW_SESSION, parameters)
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\remote\webdriver.py", line 256, in execute
self.error_handler.check_response(response)
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\remote\errorhandler.py", line 194, in check_response
raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Unable to find a matchin
g set of capabilities

按照最后一行的错误信息，从网上找到的原因是，Python3.5.2&selenium3.4.3需要有jdk8&Firefox52以上的环境
我的jdk已经是8版本的，而Firefox还是35版本的，更新Firefox到54版本后，重新执行Python就成功了。

使用chrome

修改test.py的内容：
from selenium import webdriver
import time
browser = webdriver.Chrome()
browser.get("http://www.baidu.com")
time.sleep(5)
browser.close()

需下载chromedriver：http://npm.taobao.org/mirrors/chromedriver
将chromedriver.exe配置到环境变量中，我直接放到了C:\Users\Python\Python35\，就不用再配置环境了

执行报错：
E:\python\selenium>python chrome.py
Traceback (most recent call last):
File "chrome.py", line 4, in <module>
browser.get("http://www.baidu.com")
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\remote\webdriver.py", line 268, in get
self.execute(Command.GET, {'url': url})
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\remote\webdriver.py", line 254, in execute
response = self.command_executor.execute(driver_command, params)
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\remote\remote_connection.py", line 464, in execute
return self._request(command_info[0], url, body=data)
File "C:\Users\Python\Python35\lib\site-pac
kages\selenium\webdriver\remote\remote_connection.py", line 488, in _request
resp = self._conn.getresponse()
File "C:\Users\Python\Python35\lib\http\cli
ent.py", line 1197, in getresponse
response.begin()
File "C:\Users\Python\Python35\lib\http\cli
ent.py", line 297, in begin
version, status, reason = self._read_status()
File "C:\Users\Python\Python35\lib\http\cli
ent.py", line 258, in _read_status
line = str(self.fp.readline(_MAXLINE + 1), "iso-8859-1")
File "C:\Users\Python\Python35\lib\socket.p
y", line 575, in readinto
return self._sock.recv_into(b)
ConnectionResetError: [WinError 10054] An existing connection was forcibly close
d by the remote host

按照网上的说法，应该要升级chrome或者降级chrome，由于权限限制，没有进行进一步的测试。
在chromedriver下载的网站中找到note.txt文件，上面有记载各版本chromedriver所支持的chrome版本数据：
http://chromedriver.storage.googleapis.com/2.29/notes.txt

我下载的是2.9版本，chrome只能选择31-34，因为我的chrome是57版本的，应该下载2.29（还以为2.9是最新的……）
各版本chrome下载：
http://google-chrome.en.uptodown.com/mac/old（好像没有用了）

重新执行成功