[Python知识库]python：初识 playwright 库

Playwright是由微软公司2020年初发布的新一代自动化测试工具，相较于目前最常用的Selenium，它仅用一个API即可自动执行主流浏览器(Chromium、Firefox、WebKit)自动化操作。

安装

(venv)?lifeng@apple?bin?%?pip3?install?playwright
Collecting?playwright
??Downloading?playwright-1.17.0-py3-none-macosx_10_13_x86_64.whl?(29.6?MB)
?????|████████████████████████████████|?29.6?MB?26?kB/s?????????????
Collecting?pyee>=8.0.1
??Downloading?pyee-8.2.2-py2.py3-none-any.whl?(12?kB)
Collecting?websockets>=8.1
??Downloading?websockets-10.1-cp39-cp39-macosx_10_9_x86_64.whl?(96?kB)
?????|████████████████████████████████|?96?kB?257?kB/s????????????
Requirement?already?satisfied:?greenlet>=1.0.0?in?/Users/lifeng/python-virtualenv/venv/lib/python3.9/site-packages?(from?playwright)?(1.1.2)
Installing?collected?packages:?websockets,?pyee,?playwright
Successfully?installed?playwright-1.17.0?pyee-8.2.2?websockets-10.1

安装好playwright库以后，再安装相应的浏览器：

(venv)?lifeng@apple?bin?%?playwright?install?chromium
Downloading?Playwright?build?of?chromium?v939194?-?119.9?Mb?[=======]?100%?0.0s
Playwright?build?of?chromium?v939194?downloaded?to?/Users/lifeng/Library/Caches/ms-playwright/chromium-939194
Downloading?Playwright?build?of?ffmpeg?v1006?-?1.1?Mb?[=============]?100%?0.0s
Playwright?build?of?ffmpeg?v1006?downloaded?to?/Users/lifeng/Library/Caches/ms-playwright/ffmpeg-1006
(venv)?lifeng@apple?bin?%?playwright?install?firefox?
Downloading?Playwright?build?of?firefox?v1304?-?71.7?Mb?[===========]?100%?0.0s
Playwright?build?of?firefox?v1304?downloaded?to?/Users/lifeng/Library/Caches/ms-playwright/firefox-1304
(venv)?lifeng@apple?bin?%?playwright?install?webkit?
Downloading?Playwright?build?of?webkit?v1578?-?54.2?Mb?[============]?100%?0.0s
Playwright?build?of?webkit?v1578?downloaded?to?/Users/lifeng/Library/Caches/ms-playwright/webkit-1578

Webkit 是一个开放源码的浏览器引擎 (web browser engine) ，基于 WebKit 的浏览器产品有：苹果的 Safari 和 iPhone ， Google 的 Chrome 和 Android ， Nokia 的 S60 ，傲游 3(Maxthon3) ；

用法

安装后，您可以import在 Python 脚本中使用 Playwright，并启动 3 种浏览器（chromium、firefox和webkit）中的任何一种。

from?playwright.sync_api?import?sync_playwright

with?sync_playwright()?as?p:
????#?browser?=?p.webkit.launch()
????browser?=?p.firefox.launch()
????#?browser?=?p.chromium.launch()
????page?=?browser.new_page()
????page.goto("http://www.baidu.com")
????print(page.title())
????browser.close()

Playwright库 支持 API 的两种变体：同步和异步。如果您的现代项目使用asyncio，您应该使用 async API：

import?asyncio
from?playwright.async_api?import?async_playwright


async?def?main():
????async?with?async_playwright()?as?p:
????????#?browser?=?await?p.webkit.launch()
????????#?browser?=?await?p.firefox.launch()
????????browser?=?await?p.chromium.launch()
????????page?=?await?browser.new_page()
????????await?page.goto("https://www.baidu.com")
????????print(await?page.title())
????????await?browser.close()

两种运行结果显示如下：

百度一下，你就知道

Process?finished?with?exit?code?0

第一个脚本

from?playwright.sync_api?import?sync_playwright

with?sync_playwright()?as?p:
????browser?=?p.webkit.launch()
????page?=?browser.new_page()
????page.goto("https://www.baidu.com")
????page.screenshot(path="example.png")
????browser.close()

使用webkit浏览器访问百度，然后进行截图，图片名称命名为example.png。

录制脚本

(venv)?lifeng@apple?~?%?playwright?codegen?baidu.com?

最后把录制视频的脚本复制下来，放到你的编辑器中去运行即可：

from?playwright.sync_api?import?Playwright,?sync_playwright


def?run(playwright:?Playwright)?->?None:
????browser?=?playwright.chromium.launch(headless=False)
????context?=?browser.new_context()

????#?Open?new?page
????page?=?context.new_page()

????#?Go?to?https://www.baidu.com/
????page.goto("https://www.baidu.com/")

????#?Click?input[name="wd"]
????page.click("input[name=\"wd\"]")

????#?Fill?input[name="wd"]
????page.fill("input[name=\"wd\"]",?"")

????#?Press?CapsLock
????page.press("input[name=\"wd\"]",?"CapsLock")

????#?Fill?input[name="wd"]
????page.fill("input[name=\"wd\"]",?"百度百科")

????#?Press?Enter
????#?with?page.expect_navigation(url="https://www.baidu.com/s?ie=utf-8&f=8&rsv_bp=1&rsv_idx=1&tn=baidu&wd=%E7%99%BE%E5%BA%A6%E7%99%BE%E7%A7%91&fenlei=256&rsv_pq=d14d33e400031dcf&rsv_t=8855fje1bY92gcAswotHpKJo1fjO0owlbzvdv6r4R20TSrzxKJlDNInu2LE&rqlang=cn&rsv_enter=1&rsv_dl=tb&rsv_sug3=18&rsv_sug1=15&rsv_sug7=100&rsv_sug2=0&rsv_btype=i&prefixsug=%25E7%2599%25BE%25E5%25BA%25A6%25E7%2599%25BE%25E7%25A7%2591&rsp=5&inputT=5076&rsv_sug4=5769&rsv_jmp=fail"):
????with?page.expect_navigation():
????????page.press("input[name=\"wd\"]",?"Enter")
????#?assert?page.url?==?"https://www.baidu.com/s?ie=utf-8&f=8&rsv_bp=1&rsv_idx=1&tn=baidu&wd=%E7%99%BE%E5%BA%A6%E7%99%BE%E7%A7%91&fenlei=256&rsv_pq=d14d33e400031dcf&rsv_t=8855fje1bY92gcAswotHpKJo1fjO0owlbzvdv6r4R20TSrzxKJlDNInu2LE&rqlang=cn&rsv_enter=1&rsv_dl=tb&rsv_sug3=18&rsv_sug1=15&rsv_sug7=100&rsv_sug2=0&rsv_btype=i&prefixsug=%25E7%2599%25BE%25E5%25BA%25A6%25E7%2599%25BE%25E7%25A7%2591&rsp=5&inputT=5076&rsv_sug4=5769"

????#?Click?text=百度百科
????#?with?page.expect_navigation(url="https://baike.baidu.com/"):
????with?page.expect_navigation():
????????with?page.expect_popup()?as?popup_info:
????????????page.click("text=百度百科")
????????page1?=?popup_info.value

????#?---------------------
????context.close()
????browser.close()


with?sync_playwright()?as?playwright:
????run(playwright)

playwright和selenium对比

以上就是初步了解的对比区分，但感觉playwright的前景还可以的，后续会写一些系列文章，大家共同讨论学习。

以上总结或许能帮助到你，或许帮助不到你，但还是希望能帮助到你，如有疑问、歧义，直接私信留言会及时修正发布；非常期待你的点赞和分享哟，谢谢！

未完，待续…

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文章作者：李 锋，编辑排版：梁莉莉