Flask Basic Four

Content review:

1.flask-session
From Flask Import session
From flask_session Import session

app.config["Sesstion_tpye"] = "Redis"
app.config["Sesstion_redis"] = REDIS ("IP", port,db=1)
# select 1-----[1]

Session (APP)

session["key"] = "value"
session["Key"]

2.Flask CBV
Class Index (views. Methodview):
methods = ["GET"]
decorators = [A,b,c]
Def get ():
Return "File"


App.add_url_rule ("/", endpoint= "index", View_func=index.as_view (name= "index"))

If 1:endpoint = None = name = "Index"
Elif 2:endpoint= "index"! = name= "index123"

3.Flask wtforms
From wtforms import form,validators,widgets
From Wtforms.fields Import Simple
Class Lgoinform (Form):
Username = simple. Stringfield (
label = "User Name",
validators=[
Validators. DataRequired (message= "User name cannot be empty"),
],
Widget = Widgets. TextInput (),
RENDER_KW = {"Class": "Jinwangba"}
)

Def a ():
"GET":
Return Render_template ("a.html", fm = Lgoinform ())
"POST":
Request.Form
LFM = Lgoinform (Request.Form)
Lfm.validate () True False

{{Fm.username.label}} {{Fm.username}} {{fm.username.errors.0}}

Flask Review:

# 1. Route @app.route ('/', methods=["GET", "POST"],endpoint= "HelloWorld", Strict_slashes=true)
# dynamic route parameter/<arg> def viewfunc (ARG)
# url_for
# 2. Three the base:
# HttpResponse return ' Hello world! '
# Render Retrun render_template ("index.html")
# REDIRECT Retrun redirect ("/login")

# 3.request
# Store Data:
# request.form # data obtained from the form FormData
# Request.args # data obtained when URL parameter is passed
# Request.json # Content-type:application/json Get Data
# request.data # B "" Content-type:xiaowangba Get Data
# of Request Properties
# Request.method = "GET"/"POST"
# Request.path = "/index"
# Request.url = "Http://127.0.0.1:5000/index"
# Pit
# request.values.to_dict () the same name is overridden by get (args)

# 4.session:flask-session
# App.secret_key = "Encrypted string"
# The serialized session stored in the browser cookie
# session["key"] = "value"
# session["Key"]
# session Default 31-day life cycle

# 5.Blueprint
# Blueprint objects can be understood as a flask object that cannot be started
# BP = Blueprint ("Bluename", __name__,template_folder= "Temp_blue")
# @bp. Route ("/blue")
# App.register_blueprint (BLUEPRINT.BP)

# 6.Flask Configuration
# 1.Flask Object instance Configuration
# class OBJ (object):
# DEBUG = True
# Session_type = "Redis"
# Session_redis = REDIS (db=5)
# App.config.from_object (OBJ)

# 2.Flask Initialization Configuration
# template_folder = Template file storage path
# static_folder = "Static file storage Path"
# Static_url_path = "/static file URL Access address" default is Static_folder


# 7.Flask JINJA2
# {{}} when referencing variables and executing functions, non-logical references
# {%} If for logical code reference
# obj.name Obj.get ("name") obj["name"] Obj_list.1 obj_list[1]
# Markup | Safe
# @app. Template_global ()
# @app. Template_filter ()

# 8.before_request After_request ErrorHandler (404,500)
# @app. before_request multiple before_request executed sequentially
# def BE1 ():
# return None

# @app. after_request multiple after_request, reverse order execution
# def AF1 (response)
# return response

# Normal Condition: BE1-BE2-AF2-AF1
# exception Condition: BE1-AF2-AF1
# @app. ErrorHandler (404) Redefining error messages

# 9.flash
# Flash ("BE_FR1")
# get_flashed_messages ()


# 10.send_file Jsonify
# send_file ("file path") to open and return file contents
# jsonify ({k:v}) serializes the dictionary JSON, packaging a content-type:application/json back to the client

# 11.Flask CBV
# class Index (views. Methodview):
# methods = ["GET"]
# decorators = [A,b,c]
# def get ():
# return "File"
#
#
# App.add_url_rule ("/", endpoint= "index", View_func=index.as_view (name= "index"))
#
# if 1:endpoint = None = name = "Index"
# elif 2:endpoint= "index"! = name= "index123"

1.DBUtils Database Connection Pool

First download the plugin pip install dbutils or python3-m pip install Dbutils,

Then run the MySQL database, create a new database in MySQL, and create a new table to enter the data.

ImportPymysql fromDbutils.pooleddbImportPooleddbpool=Pooleddb (creator=pymysql,#modules that use linked databasesMaxconnections=6,#the maximum number of connections allowed for a connection pool, 0 and none means no limit on the number of connectionsmincached=2,#at least 0 of the free links created in the link pool are not created when initializingMaxcached=5,#most idle links in the link pool, 0 and none are not limitedMaxshared=3,#The maximum number of links shared in a linked pool, 0 and none means sharing all. PS: Useless, because Pymysql and mysqldb modules such as threadsafety are 1, all values regardless of set to how much, _maxcached forever is 0, so forever is all links are shared. Blocking=true,#If there are no available connections in the connection pool, wait is blocked. True, wait, False, not wait and then errorMaxusage=none,#the maximum number of times a link is reused, none means unlimitedSetsession=[],#a list of commands to execute before starting the session. such as: ["Set Datestyle to ...", "Set time zone ..."]ping=0,#Ping the MySQL server to check if the service is available.     #such as: 0 = None = Never,    #1 = default = Whenever it is requested,    #2 = When a cursor is created,    #4 = When a query is executed,    #7 = alwayshost='127.0.0.1', # Host Port=3306, # Port user='Root', # User password="', # Password database='s12day113', # The name of the database created CharSet='UTF8')

You can also query a single message:

You can also insert a single piece of data:

2.Flask request Context, Application context

Flask Basic Four