def str2header(headers_raw):
    if headers_raw is None:
        return None
    headers = headers_raw.splitlines()
    headers_tuples = [header.split(':', 1) for header in headers]

    result_dict = {}
    for header_item in headers_tuples:
        if not len(header_item) == 2:
            continue
        item_key = header_item[0].strip()
        item_value = header_item[1].strip()
        result_dict[item_key] = item_value
    return result_dict 
    
#抓包看到的header字串
r_h = ''' 

GET / HTTP/1.1
Host: www.baidu.com
Connection: keep-alive
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) 
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9,en;q=0.8
Cookie: *** 

'''
#headers已經生成 可直接在requests.get(url,headers=headers)
headers=str2header(r_h)