python+selenium+ Chrome 運行中更換userAgent

通常情況下用selenium開發爬蟲時，會使用以下方式添加UA

chrome_options.add_argument('user-agent=' + self.ua)

但是每次更換需要重啟瀏覽器，這會造成資源浪費。好在selenium支持CDP,於是翻了文檔終於找到了解決方法。解決方法如下

driver.execute_cdp_cmd("Emulation.setUserAgentOverride", {
        "userAgent": "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0) Gecko/20100101 Firefox/6.0"
    })

執行后打開控制台，輸入navigator.userAgent查看，會發現userAgent已經改變，訪問任何頁面都會是目前設置的

同時官方文檔中還有以下參數可以使用：

{
                    "name": "setUserAgentOverride",
                    "description": "Allows overriding user agent with the given string.",
                    "redirect": "Emulation",
                    "parameters": [
                        {
                            "name": "userAgent",
                            "description": "User agent to use.",
                            "type": "string"
                        },
                        {
                            "name": "acceptLanguage",
                            "description": "Browser langugage to emulate.",
                            "optional": true,
                            "type": "string"
                        },
                        {
                            "name": "platform",
                            "description": "The platform navigator.platform should return.",
                            "optional": true,
                            "type": "string"
                        },
                        {
                            "name": "userAgentMetadata",
                            "description": "To be sent in Sec-CH-UA-* headers and returned in navigator.userAgentData",
                            "experimental": true,
                            "optional": true,
                            "$ref": "Emulation.UserAgentMetadata"
                        }
                    ]
                }