學生資訊資源為：

資源名稱	資源型別
學生號	int
姓名	str
年齡	int
籍貫	str
平均分	float

第一步先將資料儲存在記憶體中，使用資料庫進行資訊儲存在之後章節再繼續介紹;

1、建立flask伺服器

首先與第二章的用例相同建立一個flask的伺服器：

form flask import Flask app = Flask(__name__) @app.route('/') def welcome(): return "Welcome to studement management system!" app.run(host="192.168.1.1", post=1234, debug=True)

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form flask import Flaskapp=Flask(__name__)@app.route('/')def welcome():return"Welcome to studement management system!"app.run(host="192.168.1.1",post=1234,debug=True)

這樣就在192.168.1.1的1234埠上開啟了監聽伺服器了，此時服務端只對’/’請求有響應，其它路徑的響應都會返回404錯誤碼；

2、POST：上傳資訊

HTTP4個方法的第一個是POST，通常用來上傳資訊：

from flask import jsonify from flask import request students = [] @app.route('/student/', methods=['POST']) def add_student(): if not request.json or not 'id' in request.json or not 'name' in request.json or not 'age' int request.json or not 'birthplace' in request.json or not 'grade' in request.json: abort(400) student = { 'id' : request.json['id'], 'name' : request.json['name'], 'age' : request.json.get('age', ""), 'birthplace' : request.json.get('birthplace', ""), 'grade' : request.json['grade'] } students.append(student) return "success"

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from flask import jsonifyfrom flask import requeststudents=[]@app.route('/student/',methods=['POST'])def add_student():ifnotrequest.json ornot'id'inrequest.json ornot'name'inrequest.json ornot'age'intrequest.json ornot'birthplace'inrequest.json ornot'grade'inrequest.json:abort(400)student={'id':request.json['id'],'name':request.json['name'],'age':request.json.get('age',""),'birthplace':request.json.get('birthplace',""),'grade':request.json['grade']}students.append(student)return"success"

使用flask的request方法可以很方便的得到請求資料，使用json來進行資料傳輸也是非常好用的方法，使用curl命令來進行測試：

Python curl -i -H "Content-Type: application/json" -X POST 'http://192.168.1.1:1234/student' \ -d \ ‘{ \ “id”:1312441, \ "name":"lucy", \ "birthplace":"beijin", \ "age":20, \ "grade":90 }’

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curl-i-H"Content-Type: application/json"-XPOST'http://192.168.1.1:1234/student'\-d\‘{\“id”:1312441,\"name":"lucy",\"birthplace":"beijin",\"age":20,\"grade":90}’

注意需要將Content-Type設定為json flask的request模組才會對請求資料部分做json格式得解析；

如果返回200狀態碼並回復success，則資料新增成功；

3、PUT：更新資訊

PUT方法通常用來進行資料的更新，相應的curl命令為：

Python curl -i -H "Content-Type: application/json" -X PUT 'http://192.168.1.1:1234/student?id=1312441' \ -d \ ‘{ \ "birthplace":"beijin", \ "age":20, \ "grade":90 }’

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curl-i-H"Content-Type: application/json"-XPUT'http://192.168.1.1:1234/student?id=1312441'\-d\‘{\"birthplace":"beijin",\"age":20,\"grade":90}’

以uri中引數的數值作為key，查詢需要修改的資訊條目，服務端程式碼為：

from flask import jsonify from flask import request from flask import make_response students = [] @app.route('/students', methods = 'PUT') def update_students(): if not request.args or not 'id' in request.args: abort(400) update_id = request.args['id'] update_id = int(update_id) student = filter(lambda t: t['id'] == update_id, students) if len(student) == 0: abort(400) if not request.json: abort(403) student[0]['name'] = request.json.get('name', student[0]['name']) student[0]['age'] = request.json.get('age', student[0]['age']) student[0]['grade'] = request.json.get('grade', student[0]['grade']) student[0]['birthplace'] = request.json.get('birthplace', student[0]['birthplace']) return jsonify({student:student[0]})

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from flask import jsonifyfrom flask import requestfrom flask import make_responsestudents=[]@app.route('/students',methods='PUT')def update_students():ifnotrequest.args ornot'id'inrequest.args:abort(400)update_id=request.args['id']update_id=int(update_id)student=filter(lambdat:t['id']==update_id,students)iflen(student)==0:abort(400)ifnotrequest.json:abort(403)student[0]['name']=request.json.get('name',student[0]['name'])student[0]['age']=request.json.get('age',student[0]['age'])student[0]['grade']=request.json.get('grade',student[0]['grade'])student[0]['birthplace']=request.json.get('birthplace',student[0]['birthplace'])returnjsonify({student:student[0]})

如果找不到指定id的學生就會返回400錯誤，如果修改成功則返回修改後的學生資訊；

4、DELETE：刪除指定資訊

使用DELETE來刪除指定的學生資訊，相應的請求資訊為：

curl -X DELETE 'http://192.168.1.1:1234/student?id=1312441'

1	curl-XDELETE'http://192.168.1.1:1234/student?id=1312441'

服務端處理程式碼為

from flask import jsonify from flask import request from flask import make_response students = [] @app.route('/students', methods = 'DELETE') def delete_students(): if not request.args: abort(400) if 'id' in request.args: d_id = request.args['id'] d_id = int(d_id) student = filter(lambda t: t['id'] == d_id, students) if len(student) == 0: abort(400) students.remove(student[0]) return "success"

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from flask import jsonifyfrom flask import requestfrom flask import make_responsestudents=[]@app.route('/students',methods='DELETE')def delete_students():ifnotrequest.args:abort(400)if'id'inrequest.args:d_id=request.args['id']d_id=int(d_id)student=filter(lambdat:t['id']==d_id,students)iflen(student)==0:abort(400)students.remove(student[0])return"success"

5、GET：獲取資訊

使用GET方法獲取學生資訊，相應請求資訊為：

curl -X GET 'http://192.168.1.1:1234/student?id=1312441'

1	curl-XGET'http://192.168.1.1:1234/student?id=1312441'

服務端處理程式碼為：

from flask import jsonify from flask import request from flask import make_response students = [] @app.route('/students', methods = 'GET') def delete_students(): if not request.args: abort(400) get_id = request.args['id'] get_id = int(get_id) student = filter(lambda t: t['id'] == get_id, students) if len(student) == 0: abort(400) return jsonify({'student':student[0]})

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from flask import jsonifyfrom flask import requestfrom flask import make_responsestudents=[]@app.route('/students',methods='GET')def delete_students():ifnotrequest.args:abort(400)get_id=request.args['id']get_id=int(get_id)student=filter(lambdat:t['id']==get_id,students)iflen(student)==0:abort(400)returnjsonify({'student':student[0]})

實現了4個方法後，一個簡單的web伺服器就成型了。更復雜的功能可以在此基礎上繼續加強，下一章將介紹如何使用flask+資料庫來存取資料；