People who can achieve great things will always make warm moves , Like give it to me Point a praise
Technology stack
python
mysql
flask.pocoo.org
Chinese document ：https://dormousehole.readthedocs.io/en/latest/quickstart.html
course ：
https://flask.net.cn/tutorial/index.html
lightweight framework
Flask It's often called a microframe , Because the core functions include Werkzeug Of WSGI And routing and based on Jinja2 Template engine for . Besides ,Flask The framework also supports cookie And sessions and Web assistant , Such as JSON, Static files, etc . obviously , This is important for developing complete Web Not enough for applications . That's why we have to Flask Extension plug-in . Flask Expand to Flask The framework provides extensibility
// Read more ：https://www.yiibai.com/flask/flask_extensions.html#article-start
https://zhuanlan.zhihu.com/p/27400862
OMR Object relation mapping https://www.cnblogs.com/huanhang/p/6054908.html
SQLAlchemy It's a powerful Python ORM tool kit , Good reputation
Database connection
Database operation logic
Edit user
according to id Find the corresponding user , Update user data
user = User.query.get_404(id) # If id by none, return 404, Otherwise, return to call
Delete user
Adding roles ：
db.session.add(role)
db.session.commit() Commit to database
Add users ：
When calling the add user function , Generate a default administrator account ,
engine = create_engine('dialect+driver://username:[email protected]:port/database')
dialect： Database type
driver： Database driven selection
username： Database user name
password： User password
host： Server address
port： port
database： database
operation
session( conversation ) The concept of , It can be regarded as an object for managing persistent database connections , Below are completely transparent connection pools and transactions
get_session Under configure Can be controlled auto_commit Parameters ,= False Time write operations are not placed in transactions by default ,SQLAlchemy The default is True
session.add The function will put Model Join the current persistent space ( It can be downloaded from session.dirty notice ), until commit When the update
wtf form Protect forms from cross site scripting attacks
Inherit Form Class or subclass
Validator validator There are message Parameters ;
Required Rep is required
Form validation
Required(),validators
Judge whether the user exists
User.query.filter_by(number=field.data).first()
Inherited parent class
super(EditForm, self).__init__(*args, **kargs)Single parameter and multi parameter
Use bootstrap A predefined form style renders the entire Flask-WTF Forms ,
wtf.quick_form() The argument to the function is Flask-WTF Form object
Bootstrap
Bootstrap Is for rapid development Web Front end framework for applications and websites .Bootstrap Is based on HTML、CSS、JAVASCRIPT Of
Definition of columns
https://blog.csdn.net/liyang_nash/article/details/81163782
{% import "bootstrap/wtf.html" as wtf %}
<form class="form" method="POST">
{
{ form.hidden_tag() }}
{
{ wtf.form_field(form.title) }} % Use bootstrap Use form.title form.body form.submit Render using default
{
{ wtf.form_field(form.body) }}
{
{ wtf.form_field(form.submit) }}
</form>
Use the default style of the form to render
{% import "bootstrap/wtf.html" as wtf %}
{
{ wtf.quick_form(form) }}
Base.html
Base class
{% extends "bootstrap/base.html" %} Inherit boostrap In the base class
form.hidden_tag()
The template parameter will be replaced with a hidden field , It is used to realize the activation in the configuration CSRF Protect . If you have activated CSRF, This field needs to appear in all your forms .
Form login
StringField,PasswordField,BooleanField,SubmitField,IntegerField,FileField,
https://www.yiibai.com/flask/flask_wtf.html
Django
@app.route('/',methods=['Get','POST'])
@login_required
Decorator , Judge whether the user is logged in , Only the logged in user can access the request
and django Is the same property
The catch function throws an exception , Same as Vue Grammatical similarity
@app.errorhandler(404) #
Instructions can be used at the terminal to operate the program
command The function of the decorator , Custom command
Use scenarios ： Create some sensitive data （ Backstage Administrator ）, Batch add test data
Machine learning open source library ,, Contains many algorithms C++ Cross platform common library written by technology
dlib.get_frontal_face_detector Function to realize the visualization of face detection
1.1. be based on HOG Face detection based on feature and linear classifier Here is the classic HOG(Histogram of Oriented Gradients) features Combined with linear classifier 、 Image pyramid (image pyramid) And sliding window detection mechanism (sliding window detection scheme) Implemented face detector .
#!/usr/bin/python
# -*- coding: utf-8 -*-
import sys
import dlib
detector = dlib.get_frontal_face_detector()
def face_detect(imgfile):
win = dlib.image_window()
print("Processing file: {}".format(imgfile))
img = dlib.load_rgb_image(imgfile)
# Face detection
dets = detector(img, 1)
# len(dets) That is, the number of detected faces
print("Number of faces detected: {}".format(len(dets)))
# Traverse the coordinates of all detected faces
# left： The distance from the left side of the face to the left edge of the picture
# right： The distance from the right side of the face to the left edge of the picture
# top： Distance between the upper edge of the face and the upper edge of the picture
# bottom： The distance between the lower edge of the face and the upper edge of the picture
for i, d in enumerate(dets):
print("Detection {}: Left: {} Top: {} Right: {} Bottom: {}".format(
i, d.left(), d.top(), d.right(), d.bottom()))
win.clear_overlay()
win.set_image(img)
win.add_overlay(dets)
dlib.hit_enter_to_continue()
def face_detect_with_scores(imgfile):
win = dlib.image_window()
# If you want to get more comprehensive detection information , Such as the score of each test result (score).
# score The bigger the value is. , The higher the reliability of the test .
img = dlib.load_rgb_image(imgfile)
# The third parameter -1 Used to set and adjust the detection threshold ;
# If the parameter value is negative , Returns more results ;
# If the parameter value is a positive number , Returns fewer results .
dets, scores, idx = detector.run(img, 1, -1)
for i, d in enumerate(dets):
print("Detection {}, score: {}, face_type:{}".format(
d, scores[i], idx[i]))
win.clear_overlay()
win.set_image(img)
win.add_overlay(dets)
dlib.hit_enter_to_continue()
if __name__ == '__main__':
imgfile = "test.jpg"
face_detect(imgfile)
face_detect_with_scores(imgfile)
Use pre trained CNN Model for face detection in images .
be based on CNN The model ratio is based on HOG The face detection accuracy of feature model is higher . But more computing resources are needed , That is to say GPU Only by running on the can we have a better running speed .
#!/usr/bin/python
# -*- coding: utf-8 -*-
import sys
import dlib
# Load pre training face detection CNN Model
cnn_face_model = "mmod_human_face_detector.dat"
cnn_face_detector = dlib.cnn_face_detection_model_v1(cnn_face_model)
def cnn_face_detect(imgfile):
win = dlib.image_window()
print("Processing file: {}".format(imgfile))
img = dlib.load_rgb_image(imgfile)
# CNN Face detector
# The detector returns mmod_rectangles object, It contains mmod_rectangle objects list .
# mmod_rectangle object There are two variables ：
# [1]. dlib.rectangle object
# [2]. confidence score
dets = cnn_face_detector(img, 1)
# Batch test pictures
# dets = cnn_face_detector([image list], upsample_num, batch_size = 128)
# len(dets) That is, the number of detected faces
print("Number of faces detected: {}".format(len(dets)))
for i, d in enumerate(dets):
print("Detection {}: Left: {} Top: {} Right: {} Bottom: {} Confidence: {}".format(
i, d.rect.left(), d.rect.top(), d.rect.right(), d.rect.bottom(), d.confidence))
rects = dlib.rectangles()
rects.extend([d.rect for d in dets])
win.clear_overlay()
win.set_image(img)
win.add_overlay(rects)
dlib.hit_enter_to_continue()
if __name__ == '__main__':
imgfile = "test.jpg"
cnn_face_detect(imgfile)
https://cloud.tencent.com/developer/article/1401153
video ： hibernate
python Basics
Built in type ,getitems Just specify the method name , Many objects can write many magic functions , Iteratable properties
itenext Iterative type
call Callable type
Dynamic language , In itself, it supports polymorphic languages , There is no need to specify the type , The error will only be known at runtime
No need to inherit the specified class , Duck type is a concept of dynamic language design ;
hasattr(com,"_len__") # Determine whether the attribute is included （ Method ）
In some cases, it is necessary to determine an object type , Need abstract base class
Force a subclass to implement certain methods
Define an abstract base class , Users use it later according to their own needs , The way to realize yourself ,
Subclasses implement their own methods of the base class
abs
collections.abc
Two different base classes
Use decorators @abc.abstractmethod
During initialization, if there is no subclass or implementation , An exception will be thrown at this time , Subclasses are required to implement abstract base classes ;
template function __class__
isinstance() Judging by examples Internal function , Mandatory provisions for interfaces
isinstance and type
isinstance Check whether the type is consistent , return True perhaps False, Will find according to the inheritance relationship
is and == Symbol difference
type(b) is B # The comparison is id Are they the same? ,
== The symbol is to judge whether the values are the same
Class variables and object variables （ Instance variables ）
Variables in a class are called class variables
Initialize parameters ,self. Variables are object variables ： First, find the instance variable , Could not find the class variable that will be looked up
For class variables, you won't look for instance variables ;
class A:
aa = 0
def __init__(self,x,y):
self.x = x
self.y = y
a = A()
A.aa = 11
a.aa = 100 # Here, whether class variables are overwritten by using instances to modify class variables
print(a.aa) # 100 First, we will find in the instance aa Value
print(A.aa) # 11
__repr__()
Built in functions by overriding , To print the characters to be displayed
Use conda The virtual environment runs the project
pip install -r requirements.txt Update the database ：python app.py db upgrade
Generate administrator user ：python app.py init
function ：python app.py runserver
