Python在接口测试中的应用

1. 介绍

接口测试的方式有很多，可以使用的工具有jmeter，postman，soapUI等，也可以自己写代码进行接口测试（Python，java，go等等），工具的使用相对来说都比较简单，开箱即用。但如果接口中定义了一些需要加解密、数字签名等一些动态计算时，工具就很无助，唯有写代码进行实现测试。所以要根据接口协议，有针对性的进行选择工具，当工具不适合项目时需要进行工具开发。对于工具开发选择语言，语言本身没有优劣之分，选择自己擅长的和合适的。相对于java，go语言，Python不需要编译，而且支持的库很多，是其特点；其支持http协议接口的有urllib，urllib2以及requests库，支持websocket协议的库有websockets、websocket-client，支持grpc的库有grpcio、grpcio-tools，以及支持图形界面的PyQt5。本文中使用的Python版本为3.9.0，下面简单介绍下http、websocket、grpc接口示例，最后介绍使用PyQt5打造自己的测试工具。

2. http协议接口

对于http协议接口，requests库用起来最方便，因此采用requests库来做http协议的接口测试。安装requests：

pip install requests

2.1 GET请求示例

天气查询接口:http://wthrcdn.etouch.cn/weather_mini

import requests
r = requests.get('http://wthrcdn.etouch.cn/weather_mini')
print(r.text)

输出结果：'{"status":1002,"desc":"invilad-citykey"}'

2.2 带参数的GET请求示例

参数：city 城市名称

import requests
data ={}
data['city']='北京'
r = requests.get('http://wthrcdn.etouch.cn/weather_mini',params=data)
print(r.text)

输出结果：'{"data":{"yesterday":{"date":"31日星期二","high":"高温 27℃","fx":"南风","low":"低温 17℃","fl":"","type":"小雨"},"city":"北京","forecast":[{"date":"1日星期三","high":"高温 29℃","fengli":"","low":"低温 18℃","fengxiang":"南风","type":"晴"},{"date":"2日星期四","high":"高温 30℃","fengli":"","low":"低温 20℃","fengxiang":"南风","type":"晴"},{"date":"3日星期五","high":"高温 30℃","fengli":"","low":"低温 22℃","fengxiang":"南风","type":"阴"},{"date":"4日星期六","high":"高温 26℃","fengli":"","low":"低温 21℃","fengxiang":"南风","type":"中雨"},{"date":"5日星期天","high":"高温 26℃","fengli":"","low":"低温 20℃","fengxiang":" 东风","type":"小雨"}],"ganmao":"感冒易发期，外出请适当调整衣物，注意补充水分。","wendu":"23"},"status":1000,"desc":"OK"}'

假如服务对请求中city的一致性进行校验，header中需要传入Authorization，为city值的md5

import hashlib
data ={}
data['city']='合肥'
auth=hashlib.md5(data['city'].encode(encoding='utf-8')).hexdigest()
headers = {'Authorization': auth}
r = requests.get('http://wthrcdn.etouch.cn/weather_mini',params=data,headers=headers)
print(r.text)

输出结果：'{"data":{"yesterday":{"date":"31日星期二","high":"高温 35℃","fx":"南风","low":"低温 25℃","fl":"","type":"晴"},"city":"合肥","forecast":[{"date":"1日星期三","high":"高温 30℃","fengli":"","low":"低温 24℃","fengxiang":"北风","type":"小雨"},{"date":"2日星期四","high":"高温 26℃","fengli":"","low":"低温 23℃","fengxiang":"西北风","type":"阴"},{"date":"3日星期五","high":"高温 29℃","fengli":"","low":"低温 23℃","fengxiang":"东风","type":"多云"},{"date":"4日星期六","high":"高温 29℃","fengli":"","low":"低温 24℃","fengxiang":"东风","type":"小雨"},{"date":"5日星期天","high":"高温 31℃","fengli":"","low":"低温 24℃","fengxiang":"东北风","type":"小雨"}],"ganmao":"感冒低发期，天气舒适，请注意多吃蔬菜水果，多喝水哦。","wendu":"26"},"status":1000,"desc":"OK"}'

2.3 POST请求示例

本示例使用requests官网示例，POST请求不再多介绍，可参考官网。Github API v3 接受编码为JSON的POST数据

import json
url = 'https://api.github.com/some/endpoint'
payload = {'some': 'data'}
r = requests.post(url, data=json.dumps(payload))

3. Websocket协议接口

安装websockets库

pip install websockets

下面是一个NLP接口的例子，客户端连接服务端，发送文本，接收返回结果，其中文本需要进行base64加密。

import uuid
import websockets

async def send_msg(websocket):
    text = '我要查余额'
    bs = str(base64.b64encode(text.encode('utf-8')), 'utf-8')
    sid = uuid.uuid4()
    timestamp = str(int(time.time()) * 1000)
    msg = '{"app":"test","sn":"123","timeStamp":"' + timestamp + '","version":"1.0.0","data":"' + bs + '",' \
          '"sid":"' + str(sid) + '"} '
    print(msg)
    await websocket.send(msg)
    rev_text = await websocket.recv()
    print(rev_text)

async def client():
    async with websockets.connect('ws://xxx.xxx.com/nlp') as websocket:
        await send_msg(websocket)

if __name__ == '__main__':
    asyncio.get_event_loop().run_until_complete(client())

执行结果示例：{"appid":"test","sn":"123","timeStamp":"1630586234000","version":"1.0.0","data":"5oiR6KaB5p+l6K+i5L2Z6aKd",sid":"4c6f5a64-2374-4616-9385-376c0d25bc1e"}{"code":"0000","msg":"succ","nlp":"{"sceneKey":"","sid":"d28c7631-54d9-493e-8db8-f67a5ecc2a25","uid":"d28c7631-54d9-493e-8db8-f67a5ecc2a25","text":"我要查询余额",,"semantic":[{"intent":"querybalance","intentName":"查询余额","intentCnxt":"","template":"{Query}余额","score":0.865519,"slots":[]}],"dialog":{"status":0,"uid":"","reaction":{"text":""},"slots":null},"answer":{"answerType":"","text":"","emotion":"","topic":"","topicID":"","type":"","question":{"question":"","question_ws":""}}}","extendData":"","sid":"d28c7631-54d9-493e-8db8-f67a5ecc2a25","last":true}

4. grpc协议接口

grpc协议需要Python 3.5版本以上，安装所需的库：

pip install grpcio
pip install grpcio-tools

下面以虚拟主播服务接口为例，服务使用了grpc双向流进行交互，与服务端建立连接后，会返回一个rtmp地址，推送虚拟主播视频流，向服务端发送文本，会驱动虚拟主播播报文本。

4.1 编写avatar.proto文件

syntax = "proto3";

package protocol;

message AvatarRequest {
  string	app = 1;
  string	timestamp = 2;
  string	version = 3;
  string	anchorId = 4;
  string	vcn = 5;
  bytes		data = 6;
  int32		width = 7;
  int32		height = 8;
  string	type=9;

}

message AvatarResponse {
  string	code = 1;
  string	msg = 2;
  string	type = 3;
  bytes		data = 4;
  string	status = 5;
  string	sessionId = 6;
}

service AvatarInteraction {
  rpc Interact (stream AvatarRequest) returns (stream AvatarResponse) {
  }
}

4.2 使用工具生成grpc代码

python -m grpc_tools.protoc -I. --python_out=. --grpc_python_out=. ./avatar.proto最终生成avatar_pb2.py和avatar_pb2_grpc.py两个文件

4.3 grpc请求示例

将上述两个文件，引入到项目代码中

import sys
import threading
import time
import grpc
import avatar_pb2 as pb
import avatar_pb2_grpc as avatar


class avatarClient(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)
        self.status = False
        self.serverUrl = ""
        self.anchorId = '1001'
        self.vcn = 'xiaoyuan'
        self.app = 'testapp'
        self.type = '0'
        self.sendTxt = False
        self.text = ""
        self.connectType = '1001'
        self.pingType = '-1000'
        self.width = 1080
        self.height = 1920
        self.sid = ""
        self.print_res = printRes()
        self.lastPingTime = int(time.time() * 1000)

    # 连接服务
    def connect_sever(self):
        return pb.AvatarRequest(app=self.app, timestamp=str(int(time.time() * 1000)), version='1.0.0',
                                anchorId=self.anchorId, vcn=self.vcn, type=self.connectType, width=self.width,
                                height=self.height)

    # 发送文本
    def send_text(self):
        return pb.AvatarRequest(app=self.app, timestamp=str(int(time.time() * 1000)), version='1.0.0',
                                anchorId=self.anchorId, vcn=self.vcn, type='3', data=str(self.text).encode('utf-8'))

    # 发送ping
    def send_ping(self):
        return pb.AvatarRequest(app=self.app, timestamp=str(int(time.time() * 1000)), version='1.0.0',
                                anchorId=self.anchorId, vcn=self.vcn, type=self.pingType)

    def send_message(self):
        yield self.connect_sever()
		#间隔10秒,发送ping,进行连接保活
        while True:
            if self.sendTxt:
                yield self.send_text()
                self.sendTxt = False
            if (int(time.time() * 1000) - int(self.lastPingTime)) < 10000:
                continue
            else:
                yield self.send_ping()
                self.lastPingTime = int(time.time() * 1000)

    def run(self):
        self.status = True
        if self.serverUrl == "":
            return
        with grpc.insecure_channel(self.serverUrl) as channel:
            stub = avatar.AvatarInteractionStub(channel)
            self.channel = channel
            responses = stub.Interact(self.send_message())

            self.print_res.setClient(responses, self)
            self.print_res.start()
            time.sleep(1)
            while True:
                if self.print_res.runStatus == False:
                    break
                client.text = input("input your text:\n")
                client.sendTxt = True
                time.sleep(1)

    def stop(self):
        try:
            self.status = False
            self.print_res.runStatus = False
            time.sleep(1)
        except KeyboardInterrupt:
            pass


class printRes(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)
        self.runStatus = True

    def setClient(self, responses, client):
        self.responses = responses
        self.client = client

    def run(self):
        try:
            for response in self.responses:
                print(response)
                if not self.runStatus:
                    sys.exit(0)
                if response.code != "000000":
                    self.runStatus = False
                    sys.exit(0)
        except Exception:
            print("err")


if __name__ == '__main__':
    client = avatarClient()
    client.serverUrl = "xxx.xxx.xxx.xxx:xxxx"
    client.start()

5. 打造自己的测试工具

在编辑器中执行测试，有时候交互性不太友好，因此我们可以打造一个带交互界面的测试工具。QT是跨平台C++库的集合，它实现高级API来访问现代桌面和移动系统的许多方面。这些服务包括定位和定位服务、多媒体、NFC和蓝牙连接、基于铬的web浏览器以及传统的UI开发。PyQt5是一套针对QtV5的全面Python绑定。它被实现为超过35个扩展模块，并使Python可以作为一个替代的应用程序开发语言C++在所有支持的平台上包括IOS和Android。

5.1 安装PyQt5

pip install PyQt5

如果要使用图像界面进行设计，可以安装Qt Designer图形界面开发工具，相关配置可以自行搜索。

pip install PyQt5-tools

5.2 打造websocket测试工具

下面以websocket接口为例，实现一个nlp的测试工具

# -*- coding: utf-8 -*-
import sys
import asyncio
import base64
import time
import uuid
import websockets
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import *


class Ui_mainWindow(object):
    def __init__(self, mainWindow):
        self.mainWindow = mainWindow
        self.setupUi()

    def setupUi(self):
        self.mainWindow.setObjectName("mainWindow")
        self.mainWindow.setWindowModality(QtCore.Qt.WindowModal)
        self.mainWindow.resize(600, 300)
        self.mainWindow.setWindowTitle("NLP测试工具")

        self.centralwidget = QtWidgets.QWidget(self.mainWindow)
        self.centralwidget.setObjectName("centralwidget")

        self.widget1 = QtWidgets.QWidget(self.centralwidget)
        self.widget1.setGeometry(QtCore.QRect(10, 30, 400, 25))
        self.widget1.setObjectName("widget1")
        self.horizontalLayout = QtWidgets.QHBoxLayout(self.widget1)
        self.horizontalLayout.setContentsMargins(0, 0, 0, 0)
        self.horizontalLayout.setObjectName("horizontalLayout")

        self.serverUrlLabel = QtWidgets.QLabel(self.widget1)
        self.serverUrlLabel.setObjectName("label")
        self.serverUrlLabel.setText("服务地址:")
        self.horizontalLayout.addWidget(self.serverUrlLabel)

        self.serverUrlLineEdit = QtWidgets.QLineEdit(self.widget1)
        self.serverUrlLineEdit.setEnabled(True)
        self.serverUrlLineEdit.setText("ws://xxx..xxx.xxx/nlp")
        self.serverUrlLineEdit.setMinimumWidth(320)
        self.serverUrlLineEdit.setMaximumWidth(320)
        self.serverUrlLineEdit.setObjectName("serverUrlLineEdit")
        self.horizontalLayout.addWidget(self.serverUrlLineEdit, stretch=500, alignment=QtCore.Qt.AlignLeft)

        self.sendTextWidget = QtWidgets.QWidget(self.centralwidget)
        self.sendTextWidget.setGeometry(QtCore.QRect(0, 70, 500, 70))
        self.sendTextWidget.setObjectName("sendTextWidget")
        self.sendTextLayout = QtWidgets.QHBoxLayout(self.sendTextWidget)
        self.sendTextLayout.setContentsMargins(0, 0, 0, 0)
        self.sendTextLayout.setObjectName("sendTextLayout")

        self.sendTextLabel = QtWidgets.QLabel(self.sendTextWidget)
        self.sendTextLabel.setContentsMargins(20, 0, 0, 0)
        self.sendTextLabel.setText("文本:")
        self.sendTextLayout.addWidget(self.sendTextLabel)

        self.sendTextTextEdit = QtWidgets.QTextEdit(self.sendTextWidget)
        self.sendTextTextEdit.setObjectName("sendTextTextEdit")
        self.sendTextLayout.addWidget(self.sendTextTextEdit)

        self.sendTextButton = QtWidgets.QPushButton(self.sendTextWidget)
        self.sendTextButton.setObjectName("sendText")
        self.sendTextButton.setText("发送")
        self.sendTextButton.clicked.connect(self.send_text)
        self.sendTextLayout.addWidget(self.sendTextButton)

        self.widget3 = QtWidgets.QWidget(self.centralwidget)
        self.widget3.setGeometry(QtCore.QRect(0, 160, 420, 90))
        self.widget3.setObjectName("widget3")

        self.logLayout = QtWidgets.QHBoxLayout(self.widget3)
        self.logLayout.setContentsMargins(0, 0, 0, 0)
        self.logLayout.setObjectName("logLayout")

        self.logLabel = QtWidgets.QLabel(self.widget3)
        self.logLabel.setObjectName("logLabel")
        self.logLabel.setContentsMargins(20, 0, 0, 0)
        self.logLabel.setLineWidth(30)
        self.logLabel.setText("返回:")
        self.logLayout.addWidget(self.logLabel)

        self.logTextEdit = QtWidgets.QTextEdit(self.widget3)
        self.logTextEdit.setContentsMargins(0, 0, 0, 0)
        self.logTextEdit.setObjectName("logTextEdit")
        self.logLayout.addWidget(self.logTextEdit)

        self.mainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(self.mainWindow)
        self.statusbar.setObjectName("statusbar")
        self.mainWindow.setStatusBar(self.statusbar)

        QtCore.QMetaObject.connectSlotsByName(self.mainWindow)

    def send_text(self):
        self.websocketClient = WebsocketClient()
        self.websocketClient.url = self.serverUrlLineEdit.text()
        self.websocketClient.text = self.sendTextTextEdit.toPlainText()
        result = self.websocketClient.run()
        self.logTextEdit.setText(result)

class WebsocketClient:
    def __init__(self):
        self.url = ""

    async def send_msg(self, websocket):
        if self.text == "":
            return "empty text"
        bs = str(base64.b64encode(self.text.encode('utf-8')), 'utf-8')
        sid = uuid.uuid4()
        timestamp = str(int(time.time()) * 1000)
		msg = '{"app":"test","sn":"123","timeStamp":"' + timestamp + '","version":"1.0.0","data":"' + bs + '",' \
			'"sid":"' + str(sid) + '"} '
        await websocket.send(msg)
        rev_text = await websocket.recv()
        self.result = rev_text
        self.text = ""
        return rev_text

    async def connect(self):
        try:
            async with websockets.connect(self.url) as websocket:
                res = await self.send_msg(websocket)
                return res
        except Exception as e:
            return str(e)

    def run(self):
        return asyncio.get_event_loop().run_until_complete(self.connect())


if __name__ == "__main__":
    app = QApplication(sys.argv)
	window = QMainWindow()
	box = Ui_mainWindow(window)
	window.show()
    sys.exit(app.exec_())

执行结果：

5.3 虚拟主播工具介绍

上一节中，介绍了虚拟主播服务grpc接口示例，那么可以使用PyQt5打造虚拟主播的测试工具，此处不再提供示例代码，运行如下图：