使用python向RESTful API发出请求

Question

我有一个RESTful API，我在EC2实例上使用Elasticsearch的一个实现来索引一个内容语料库。我可以从我的终端（MacOSX）运行以下命令来查询搜索：

curl -XGET 'http://ES_search_demo.com/document/record/_search?pretty=true' -d '{
  "query": {
    "bool": {
      "must": [
        {
          "text": {
            "record.document": "SOME_JOURNAL"
          }
        },
        {
          "text": {
            "record.articleTitle": "farmers"
          }
        }
      ],
      "must_not": [],
      "should": []
    }
  },
  "from": 0,
  "size": 50,
  "sort": [],
  "facets": {}
}'

如何使用python/requests或python/urllib2将上面的内容转换为API请求（不确定要使用哪个-一直在使用urllib2，但听说请求更好…）？我是头球还是其他传球？

Answer 1

所以您希望在GET请求的主体中传递数据，最好是在POST调用中这样做。您可以通过使用这两个请求来实现这一点。

原始请求

GET http://ES_search_demo.com/document/record/_search?pretty=true HTTP/1.1
Host: ES_search_demo.com
Content-Length: 183
User-Agent: python-requests/2.9.0
Connection: keep-alive
Accept: */*
Accept-Encoding: gzip, deflate

{
  "query": {
    "bool": {
      "must": [
        {
          "text": {
            "record.document": "SOME_JOURNAL"
          }
        },
        {
          "text": {
            "record.articleTitle": "farmers"
          }
        }
      ],
      "must_not": [],
      "should": []
    }
  },
  "from": 0,
  "size": 50,
  "sort": [],
  "facets": {}
}

带请求的示例调用

import requests

def consumeGETRequestSync():
data = '{
  "query": {
    "bool": {
      "must": [
        {
          "text": {
            "record.document": "SOME_JOURNAL"
          }
        },
        {
          "text": {
            "record.articleTitle": "farmers"
          }
        }
      ],
      "must_not": [],
      "should": []
    }
  },
  "from": 0,
  "size": 50,
  "sort": [],
  "facets": {}
}'
url = 'http://ES_search_demo.com/document/record/_search?pretty=true'
headers = {"Accept": "application/json"}
# call get service with headers and params
response = requests.get(url,data = data)
print "code:"+ str(response.status_code)
print "******************"
print "headers:"+ str(response.headers)
print "******************"
print "content:"+ str(response.text)

consumeGETRequestSync()

Answer 2

使用requests和json使其变得简单。

1. 调用API
2. 假设API返回JSON，将JSON对象解析为 Python dict使用json.loads函数
3. 遍历dict以提取信息。

Requests模块提供有用的函数来循环成功和失败。

if(Response.ok)：将帮助您确定您的API调用是否成功（响应代码-200）

Response.raise_for_status()将帮助您获取从API返回的http代码。

下面是进行此类API调用的示例代码。也可以在github中找到。代码假设API使用摘要式身份验证。您可以跳过此步骤，也可以使用其他适当的身份验证模块对调用API的客户端进行身份验证。

#Python 2.7.6
#RestfulClient.py

import requests
from requests.auth import HTTPDigestAuth
import json

# Replace with the correct URL
url = "http://api_url"

# It is a good practice not to hardcode the credentials. So ask the user to enter credentials at runtime
myResponse = requests.get(url,auth=HTTPDigestAuth(raw_input("username: "), raw_input("Password: ")), verify=True)
#print (myResponse.status_code)

# For successful API call, response code will be 200 (OK)
if(myResponse.ok):

    # Loading the response data into a dict variable
    # json.loads takes in only binary or string variables so using content to fetch binary content
    # Loads (Load String) takes a Json file and converts into python data structure (dict or list, depending on JSON)
    jData = json.loads(myResponse.content)

    print("The response contains {0} properties".format(len(jData)))
    print("\n")
    for key in jData:
        print key + " : " + jData[key]
else:
  # If response code is not ok (200), print the resulting http error code with description
    myResponse.raise_for_status()

Answer 3

使用requests：

import requests
url = 'http://ES_search_demo.com/document/record/_search?pretty=true'
data = '''{
  "query": {
    "bool": {
      "must": [
        {
          "text": {
            "record.document": "SOME_JOURNAL"
          }
        },
        {
          "text": {
            "record.articleTitle": "farmers"
          }
        }
      ],
      "must_not": [],
      "should": []
    }
  },
  "from": 0,
  "size": 50,
  "sort": [],
  "facets": {}
}'''
response = requests.post(url, data=data)

根据API返回的响应类型，您可能需要查看response.text或response.json()（或者可能首先检查response.status_code）。请参阅快速启动文档here，特别是this section。