前言
由于最近很多android手机升级到7.0系统了，有些小伙伴的appium版本用的还是1.4版本，在运行android7.0的app自动化时候遇到无法启动问题：WebDriverException: Message: A new session could not be created
我的电脑环境：
- python 3.6
- android 7.0
- appium 1.4.13
android7.0遇到问题
1.执行代码：
# coding:utf-8
# 作者：上海-悠悠
from appium import webdriver
from time import sleep desired_caps = { 'platformName': 'Android', 'deviceName': 'A5RNW18316011440', 'platformVersion': '7.0', 'appPackage': 'com.baidu.yuedu', 'appActivity': 'com.baidu.yuedu.splash.SplashActivity' } driver = webdriver.Remote('http://127.0.0.1:4723/wd/hub', desired_caps)2.执行后报错如下：A new session could not be created
D:\soft\python3.6\python.exe D:/xcm_app_test/app/test_login.py
Traceback (most recent call last):
File "D:/xcm_app_test/app/test_login.py", line 11, in <module> driver = webdriver.Remote('http://127.0.0.1:4723/wd/hub', desired_caps) File "D:\soft\python3.6\lib\site-packages\appium\webdriver\webdriver.py", line 36, in __init__ super(WebDriver, self).__init__(command_executor, desired_capabilities, browser_profile, proxy, keep_alive) File "D:\soft\python3.6\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 90, in __init__ self.start_session(desired_capabilities, browser_profile) File "D:\soft\python3.6\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 177, in start_session response = self.execute(Command.NEW_SESSION, capabilities) File "D:\soft\python3.6\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 236, in execute self.error_handler.check_response(response) File "D:\soft\python3.6\lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 192, in check_response raise exception_class(message, screen, stacktrace) selenium.common.exceptions.WebDriverException: Message: A new session could not be created. (Original error: Command failed: )分析问题
1.遇到无法启动问题，报错都一样：A new session could not be created，看编辑器报错是没啥用的，这个时候就需要打开appium的日志界面，分析走到哪一步报错了,日志太多，就贴一部分了
> info: [debug] Device is at API Level 24
> info: Device API level is: 24
> info: [debug] Extracting strings for language: default > info: [debug] Apk doesn't exist locally > info: [debug] Could not get strings, but it looks like we had an old strings file anyway, so ignoring2.从上面日志可以看出，当前的设备API版本是24，而appium1.4支持的最高API版本是23。打开appium客户端，左上角点机器人图标，点开platformVersion如下图所示
3.也就是说appium1.4支持最高android版本是6.0，查下资料可以知道android7.0需使用appium1.6.3以上版本才能支持。
解决问题
1.重新下载最新版appium，appium1.6以后版本都是以appium-desktop命名的，目前我使用的版本是appium-desktop1.2.2，安装完之后也就是V1.7.1版本
2.appium-desktop所以版本在github都能下载到：
appium-desktop 所有版本下载地址
3.appium-desktop和之前老的appium版本是可以共存的，所有不需要卸载之前的版本，重新打开appium1.7版本，运行代码
4.重新运行时候发现报这个错,从报错信息看是手机上安装的unlock版本不匹配（因为之前运行appium1.4版本有残留），解决办法：手动卸载手机上的appium settings和Unlock就可以了
selenium.common.exceptions.WebDriverException: Message: An unknown server-side error occurred while processing the command. Original error: Error executing adbExec. Original error: 'Command 'D\:\\soft\\Android\\platform-tools\\adb.exe -P 5037 -s A5RNW18316011440 install C\:\\Users\\admin\\AppData\\Local\\Programs\\appium-desktop\\resources\\app\\node_modules\\appium\\node_modules\\appium-unlock\\bin\\unlock_apk-debug.apk' exited with code 1'; Stderr: 'Failed to install C:\Users\admin\AppData\Local\Programs\appium-desktop\resources\app\node_modules\appium\node_modules\appium-unlock\bin\unlock_apk-debug.apk: Failure [INSTALL_FAILED_UPDATE_INCOMPATIBLE: Package io.appium.unlock signatures do not match the previously installed version; ignoring!]'; Code: '1'备注
1.有些小伙伴可能用的appium1.6版本，可以尝试加上这个参数，用uiautomator2运行
'automationName': 'uiautomator2'
# coding:utf-8
# 作者：上海-悠悠
from appium import webdriver
from time import sleep desired_caps = { 'platformName': 'Android', 'deviceName': 'A5RNW18316011440', 'platformVersion': '7.0', 'automationName': 'uiautomator2', 'appPackage': 'com.baidu.yuedu', 'appActivity': 'com.baidu.yuedu.splash.SplashActivity' } driver = webdriver.Remote('http://127.0.0.1:4723/wd/hub', desired_caps)