Python+Appium自动化测试(14)-yaml配置Desired capabilities

一，前言

在之前的appium自动化测试示例中，我们都是把构造driver实例对象的数据（即Desired Capabilities）写在业务代码里，如下：

# -*- coding:utf-8 -*-
# @author: 给你一页白纸

from appium import webdriver

desired_caps = {
    "platformName": "Android",
    "platformVersion": "10",
    "deviceName": "PCT_AL10",
    "appPackage": "com.ss.android.article.news",
    "appActivity": ".activity.MainActivity",
    "automationName": "UiAutomator2",
    "unicodeKeyboard": True,
    "resetKeyboard": True,
    "noReset": True,
}
driver = webdriver.Remote('http://127.0.0.1:4723/wd/hub', desired_caps)

这种情况下，如果我们要更换测试机测试的话，就需要去代码里面修改这些信息，从项目维护的角度来说显然是不方便的，应该考虑将这些测试配置信息写在专门的配置文件里，使用的时候直接调用即可。

二，使用yaml文件配置Capabilities示例

目录结构如下：

config下的desired_caps.yml文件里capabilities数据如下（Python中yaml文件的读写方法点这里）：

platformName: Android
platformVersion: '10'
deviceName: PCT_AL10
appActivity: .activity.MainActivity
appPackage: com.ss.android.article.news
automationName: UiAutomator2
resetKeyboard: true
noReset: true
unicodeKeyboard: true
ip: 127.0.0.1
port: 4723

common下的baseDriver.py文件中构造driver的函数如下：

# -*- coding:utf-8 -*-
# @author: 给你一页白纸

import yaml, os
from appium import webdriver

# 项目根目录路径，即android-ui-autotest文件夹的路径
BASE_PATH = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
# capabilities配置文件desired_caps.py路径
DESIRED_CAPS_YAML_PATH = CONFIG_PATH + '/config/desired_caps'

def android_driver():
    # 从desired_caps.yaml读取driver配置数据
    stream = open(DESIRED_CAPS_YAML_PATH, 'r')
    data = yaml.load(stream, Loader=yaml.FullLoader)

    desired_caps = {}
    desired_caps['platformName'] = data['platformName']
    desired_caps['platformVersion'] = data['platformVersion']
    desired_caps['deviceName'] = data['deviceName']
    desired_caps['appPackage'] = data['appPackage']
    desired_caps['appActivity'] = data['appActivity']
    desired_caps['automationName'] = data['automationName']  
    desired_caps['unicodeKeyBoard'] = data['unicodeKeyBoard']
    desired_caps['resetKeyboard'] = data['resetKeyboard']
    desired_caps['noReset'] = data['noReset']

    driver = webdriver.Remote('http://' + str(data['ip']) + ':' + str(data['port']) + '/wd/hub', desired_caps)
    driver.implicitly_wait(8)

    return driver

三，更新yaml文件的内容

有时候我们需要通过脚本修改yaml文件里的配置信息。比如更换了测试机，capabilities里的platformVersion、deviceName都变了，脚本自动获取新测试机的这两个参数，并更新至desired_caps.yml文件里。

更新yaml文件思路：

1，先读取需要更新的yaml文件的内容；

2，将读取内容里需要更改内容替换成新的内容；

3，再写入yaml文件。

示例代码如下：

# -*- coding:utf-8 -*-
# @author: 给你一页白纸

import yaml

def update_yaml():
    with open('./config/desired_caps', 'r',  encoding='utf-8') as f:
        content = yaml.load(f, Loader=yaml.FullLoader)

    content['platformVersion'] = 'newPlatformVersion'
    content['deviceName'] = 'newDeviceName'

    with open('./config/desired_caps', 'w', encoding='utf-8') as nf:
        yaml.dump(data=content, stream=nf, allow_unicode=True)