Flash build API service

Flask It's a use Python Written lightweight Web Application framework , Very suitable for personal development , We make an interface here .

For the convenience of debugging , This article USES the get The interface way .get The interface is very simple , There is no need to upload any data , Add a... After the path get The method can be used , The returned string is .

This article is just Flask Preliminary documentation of the developed interface , From the simplest interface development to the slightly more complex interface , If there is time in the future , Will gradually improve , Include token authentication 、 Cross domain authentication 、 Blueprint application 、 Log management, etc .

First step , First, in the configs Configure data source in

configs.py

HOST = '127.0.0.1'
PORT = '5432'
DATABASE = 'runoobdb'
USERNAME = 'postgres'
PASSWORD = '*****'
#  Configure the main database 
DB_URI = "postgresql+psycopg2://{username}:{password}@{host}:{port}/{db}".format(username=USERNAME, password=PASSWORD,
                                                                                 host=HOST, port=PORT, db=DATABASE)
# SQLALCHEMY_DATABASE_URI = 'postgresql+psycopg2://postgres:*****@127.0.0.1:5432/runoobdb'
#  Connect to other databases 
SQLALCHEMY_BINDS = {
    'xxxdb': 'postgresql+psycopg2://postgres:[email protected]:5432/lincms3',
    'yyydb': 'postgresql+psycopg2://postgres:[email protected]:5432/lincms4',
    'zzzdb': 'sqlite:///users.db'
}
SQLALCHEMY_DATABASE_URI = DB_URI
SQLALCHEMY_TRACK_MODIFICATIONS = False
SQLALCHEMY_ECHO = True

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The second step , stay exts Define global in db

exts.py

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

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The third step , Constructed a flaskutils, Define some public classes to which the interface applies , For example, data transcoding , Convert the data set to json, analysis url Comma parameter, etc , The functions will be expanded on this basis in the future .

flaskutils.py

import decimal

import numpy as np
import json, datetime,configparser


class DataEncoder(json.JSONEncoder):
    """ Data transcoding class     """
    def default(self, obj):
        """ For unable to transfer json Transcoding the data type of 
         Currently supported transcoding types         1、 take Numpy Of intger,floating To int and float
        2、 take Numpy Of ndarray To list
        3、 take np.datetime64 Before converting to string 10 position         4、 take datetime.datetime Turn into "%Y-%m-%d %H:%M:%S"
        5、 take datetime.date Turn into "%Y-%m-%d"
        6、 take bytes Turn into utf-8 character string 
         Enter the reference :
            obj:  Data objects 
         The ginseng :
             Transformed data 
         abnormal :
             nothing         """
        if isinstance(obj, np.integer):
            return int(obj)
        elif isinstance(obj, np.floating):
            return float(obj)
        elif isinstance(obj, np.ndarray):
            return obj.tolist()
        elif isinstance(obj, np.datetime64):
            return str(obj)[:10]
        elif isinstance(obj, datetime.datetime):
            return obj.strftime("%Y-%m-%d %H:%M:%S")
        elif isinstance(obj, datetime.date):
            return obj.strftime("%Y-%m-%d")
        elif isinstance(obj, decimal.Decimal):
            return float(obj)
        elif isinstance(obj, bytes):
            return str(obj, encoding='utf-8')
        else:
            return json.JSONEncoder.default(self, obj)


def getsqlresultjson(db, sql,params={}):
    """ according to db and sql sentence , Convert result set to json Format 
     according to db and sql sentence , Convert result set to json Format 
     First step ： according to cursor Fetch metadata , Generate key value list 
     The second step ： Traversal result set , Assemble the key value list and result set into a dictionary , Join list 
     The third step ： Pass the list through DataEncoder Transcoding 
     Enter the reference :
        db:  Database instance .
        sql:  To be run SQL sentence 
     The ginseng :
        Json Format :
         give an example ：        {'Serak': ('Rigel VII', 'Preparer'),
          'Zim': ('Irk', 'Invader'),
         'Lrrr': ('Omicron Persei 8', 'Emperor')}
     abnormal :
         nothing     """
    resultdict = []

    cursor = db.session.execute(sql,params=params).cursor
    resultproxy = db.session.execute(sql,params=params).fetchall()

    #  Fetch metadata 
    colname = [i[0] for i in cursor.description]
    #  Get the result set , Make up a dictionary , Join list 
    for rowproxy in resultproxy:
        rowresult = dict(zip(colname, rowproxy))
        resultdict.append(rowresult)

    #  Generate json Format 
    jsonstr = json.dumps(resultdict, cls=DataEncoder)
    return jsonstr


def parasecommaparamtolist(param):
    '''
     Handle in Pass parameters ,in The transfer parameters can be applied to two transfer methods , Comma passing parameter or parameter passing 
     Here we mainly deal with , Pass arguments with commas , Return to list
    # http://127.0.0.1:5000/getresultbysqlgetparaminbylist?sqlid=sql10&begindate=2018&enddate=2020&kpicode=03010101
    # http://127.0.0.1:5000/getresultbysqlgetparaminbylist?sqlid=sql10&begindate=2018&enddate=2020&kpicode=03010101&kpicode=031111111
    # http://127.0.0.1:5000/getresultbysqlgetparaminbylist?sqlid=sql10&begindate=2018&enddate=2020
    # http://127.0.0.1:5000/getresultbysqlgetparaminbylist?sqlid=sql10&begindate=2018&enddate=2020&kpicode=03010101,222222222
    # http://127.0.0.1:5000/getresultbysqlgetparaminbylist?sqlid=sql10&begindate=2018&enddate=2020&kpicode=03010101&kpicode=03010101
    :param param:
    :return:
         String list     '''
    result = []
    for val in param.split(','):
        if val:
            result.append(val)
    return result

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Step four , stay app File build initial version

app.py

import configs
from exts import db
from flask import Flask
from flaskutils import *
from flask import request,jsonify

app = Flask(__name__)

#  Load profile 
app.config.from_object(configs)
app.debug = True

db.init_app(app)

if __name__ == '__main__':
    print(app.url_map)
    app.run(host='0.0.0.0', port=8080)

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Step five , stay app Configuration in file sql sentence , I wanted to try mybis Type of profile , Later decided to simplify ; It mainly includes three items sql, Article 1 no reference is required , Second, pass the general parameters , Article 3 transmission in Parameters , In especial in Parameters , Basically, the methods found on the Internet are not reliable , This article is original .

sqldict={}
sqldict['sql1'] = """select a.*
from kpi_value a
where a.kpicode in ('01010101','02010101','03010101')
and a.datelevel='01'
and a.regionlevel='02'
"""
sqldict['sql2'] = """select a.*
from kpi_value a
where a.kpicode in ('01010101','02010101','03010101')
and a.datelevel='01'
and a.regionlevel='02'
and a.datecode>=:begindate and a.datecode<=:enddate
"""
sqldict['sql3'] = """select a.*
from kpi_value a
and a.datelevel='01'
and a.regionlevel='02'
and a.datecode>=:begindate and a.datecode<=:enddate
and a.kpicode in :kpicode
"""

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1、 Constructing the first one is the simplest sql Return Interface , There is no need to pass on sql Parameters , But you need to pass sqlid Parameters

@app.route('/getresultbysql', methods=['GET', 'POST'])
def index1():
    sqlid = request.args.get('sqlid')
    sqltext=sqldict[sqlid]
    jsonstr = getsqlresultjson(db,sqltext)
    return jsonstr, 200, {"Content-Type": "application/json"}

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2、 Construct a sql Interface for internal parameter transfer , By means of dictionary parameters

@app.route('/getresultbysqlparam', methods=['GET', 'POST'])
def index2():
    sqlid = request.args.get('sqlid')
    sqltext=sqldict[sqlid]
    params = {"begindate": '2017',"enddate":'2019'}
    jsonstr = getsqlresultjson(db,sqltext,params)
    return jsonstr, 200, {"Content-Type": "application/json"}

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3、 adopt url Conduct sql Parameter passing .

@app.route('/getresultbysqlgetparam', methods=['GET', 'POST'])
def index3():
    sqlid = request.args.get('sqlid')
    begindate = request.args.get('begindate')
    enddate = request.args.get('enddate')
    sqltext=sqldict[sqlid]
    params = {"begindate": begindate,"enddate":enddate}
    jsonstr = getsqlresultjson(db,sqltext,params)
    return jsonstr, 200, {"Content-Type": "application/json"}

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4、 adopt url Conduct sql Parameter passing , But don't pass in Parameters , Instead, it is specified in the routing function summary in Parameters

@app.route('/getresultbysqlgetparamin', methods=['GET', 'POST'])
def index4():
    sqlid = request.args.get('sqlid')
    sqlid='sql3'
    begindate = request.args.get('begindate')
    enddate = request.args.get('enddate')
    sqltext=sqldict[sqlid]
    incond = ['01010101',  '03010101']
    params = {"begindate": begindate,"enddate":enddate,'kpicode':tuple(incond)}
    jsonstr = getsqlresultjson(db,sqltext,params)
    return jsonstr, 200, {"Content-Type": "application/json"}

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5、 adopt url Conduct in The transfer of parameters and common parameters , There are two ways to support this , One is &aa=xxx&aa=yyy, One is aa=xxx,yyy.

@app.route('/getresultbysqlgetparaminbylist', methods=['GET', 'POST'])
def index5():
    sqlid = request.args.get('sqlid')
    sqlid='sql3'
    begindate = request.args.get('begindate')
    enddate = request.args.get('enddate')
    incond=request.args.getlist('kpicode')

    if len(incond) == 1 and ',' in incond[0]:
        incond = parasecommaparamtolist(incond[0])

    sqltext=sqldict[sqlid]
    params = {"begindate": begindate,"enddate":enddate,'kpicode':tuple(incond)}
    jsonstr = getsqlresultjson(db,sqltext,params)

    return jsonstr, 200, {"Content-Type": "application/json"}

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6、 The standardized interface response returns the result .

@app.route('/getresultbysqlgetparaminbylistresponse', methods=['GET', 'POST'])
def index6():

    retinfo={}
    errorflag=False
    retinfo['returncode'] = 200
    retinfo['returndata'] = ''
    retinfo['returninfo'] = ' Processing results '
    sqlid = request.args.get('sqlid')
    begindate = request.args.get('begindate')
    enddate = request.args.get('enddate')
    incond = request.args.getlist('kpicode')

    if len(incond) == 1 and ',' in incond[0]:
        incond = parasecommaparamtolist(incond[0])
    if not incond:
        retinfo['returninfo']=retinfo['returninfo'] +' No incoming KPI code '
        errorflag=True
    if not begindate:
        retinfo['returninfo'] = retinfo['returninfo'] + ' No start time was passed in '
        errorflag=True
    if not enddate:
        retinfo['returninfo'] = retinfo['returninfo'] + ' End time not passed in '
        errorflag=True
    if begindate>enddate:
        retinfo['returninfo'] = retinfo['returninfo'] + ' The start time is greater than the end time '
        errorflag=True
    if errorflag==True:
        retinfo['returncode'] = 400
        response = jsonify(retinfo)
        response.status_code = 400
        return response

    sqltext = sqldict[sqlid]
    params = {"begindate": begindate, "enddate": enddate, 'kpicode': tuple(incond)}
    jsonstr = getsqlresultjson(db, sqltext, params)
    retinfo['returndata']  = jsonstr
    response = jsonify(retinfo)
    response.status_code = 200
    return response

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Last , Thank you for your attention , Thank you for your support ！