如何通过requests模块触发USPS打印商目录的Apply Filters按钮？

访问指定网页并输入搜索地址New York City, New York, USA后，网页会显示搜索结果，以下Python脚本可实现该基础功能。但现在需要通过Filter results按钮设置筛选条件：

• SERVICES选择Printing your mailpiece
• DISTANCE选择within 50 miles
• SORT选择By distance
  触发Apply Filters按钮完成结果筛选，目前无法用requests模块实现该操作。

原脚本代码：

import time
import requests

url = 'https://printerdirectory.usps.com/listing/api/vendors'
link = 'https://gis.usps.com/arcgis/rest/services/locators/EDDM_Composite/GeocodeServer/suggest'
params = {
    'text': 'New York City, New York, USA',
    'f': 'json'
}
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
    'Accept': 'application/json, text/plain, */*',
    'Accept-Encoding': 'gzip, deflate, br',
    'Accept-Language': 'en-US,en;q=0.9',
    'Origin': 'https://printerdirectory.usps.com',
    'Referer': 'https://printerdirectory.usps.com/'
}
result_params = {
    'noCache': ''
}
result_headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
    'Accept': 'application/json, text/plain, */*',
    'Accept-Encoding': 'gzip, deflate, br',
    'Accept-Language': 'en-US,en;q=0.9',
    'Host': 'printerdirectory.usps.com',
    'Referer': 'https://printerdirectory.usps.com/listing/',
    'Location': '',
    'Key': '',
    'Type': 'key',
    'Lazyupdate': '[object Object]'
}

with requests.Session() as s:
    s.headers.update(headers)
    res = s.get(link,params=params)
    result_headers['Location'] = res.json()['suggestions'][0]['text']
    result_headers['Key'] = res.json()['suggestions'][0]['magicKey']
    s.headers.update(result_headers)
    unixtime = int(time.time()*1000)
    result_params['noCache'] = unixtime
    resp = s.get(url,params=result_params)
    print(resp.json()['vendors'])

请问如何通过requests模块实现Apply Filters按钮的功能？

要实现筛选功能，核心是分析网页点击Apply Filters时实际发送的请求参数。通过抓包可以发现，筛选条件是通过GET请求的查询参数传递的，只需在原请求的result_params中添加对应的筛选参数即可：

1. 服务筛选参数：services=Printing your mailpiece
2. 距离筛选参数：distance=50（对应within 50 miles）
3. 排序参数：sort=distance（对应By distance）

修改后的完整脚本如下：

import time
import requests

url = 'https://printerdirectory.usps.com/listing/api/vendors'
link = 'https://gis.usps.com/arcgis/rest/services/locators/EDDM_Composite/GeocodeServer/suggest'
params = {
    'text': 'New York City, New York, USA',
    'f': 'json'
}
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
    'Accept': 'application/json, text/plain, */*',
    'Accept-Encoding': 'gzip, deflate, br',
    'Accept-Language': 'en-US,en;q=0.9',
    'Origin': 'https://printerdirectory.usps.com',
    'Referer': 'https://printerdirectory.usps.com/'
}

# 新增筛选参数
result_params = {
    'noCache': '',
    'services': 'Printing your mailpiece',
    'distance': '50',
    'sort': 'distance'
}

result_headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
    'Accept': 'application/json, text/plain, */*',
    'Accept-Encoding': 'gzip, deflate, br',
    'Accept-Language': 'en-US,en;q=0.9',
    'Host': 'printerdirectory.usps.com',
    'Referer': 'https://printerdirectory.usps.com/listing/',
    'Location': '',
    'Key': '',
    'Type': 'key',
    'Lazyupdate': '[object Object]'
}

with requests.Session() as s:
    s.headers.update(headers)
    res = s.get(link, params=params)
    # 处理地址建议为空的情况
    if not res.json().get('suggestions'):
        print("未获取到有效地址建议")
        exit()
    result_headers['Location'] = res.json()['suggestions'][0]['text']
    result_headers['Key'] = res.json()['suggestions'][0]['magicKey']
    s.headers.update(result_headers)
    
    unixtime = int(time.time()*1000)
    result_params['noCache'] = unixtime
    
    resp = s.get(url, params=result_params)
    # 检查请求状态
    if resp.status_code == 200:
        print(resp.json()['vendors'])
    else:
        print(f"请求失败，状态码：{resp.status_code}")

补充说明 #

• 可以通过浏览器开发者工具（F12）抓包，观察点击Apply Filters时的请求URL，直接提取所需的筛选参数。
• 保持Session会话可维持必要的请求头和状态，避免因请求不完整被服务器拒绝。
• 新增的错误处理逻辑，可避免因地址建议为空或请求失败导致的程序崩溃。

内容的提问来源于stack exchange，提问作者robots.txt