Fastapi learning Day1

Catalog

install pyCharm

Create project

install FastAPI Tools for

Use FastAPI

notes

send out post request , use postman test

obtain URL Parameters

Request header pass parameters Header

Request body passing parameters

json Format transfer data ,Body class

form Transfer data in form format , Import Form class

Modify response status code

JSONResponse The format of the returned data is json object

 HTMLResponse The way to return data is html page

FileResponse The way to return data is by file

Return through the template engine HTML page

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install pyCharm

Download Community Edition , Just refer to other bloggers , Note that file——settings——project——project interpreter Package management

Using skills

file——Settings——Appearance Set the background color and the font and font size of the toolbar

 file——Settings——Editor——font Set the font size and line spacing of the editing page

 file——Settings——Editor——File Encodings  Set the encoding form

FastAPI yes python web frame , The focus is on asynchronous programming ,python3.6 Above version

It can be used FastAPI Develop web site 、 Development web API、 Make a test platform 、 Continuous integration tools 、 Generating documentation

Create project

choice new environment using Will create a venv Virtual environment for , The advantage of this is that each project is an independent space , There will be no version dependency conflicts , It will not pollute the previous system environment

choice previously configured interpreter, The previously configured interpreter , Then select the... On your computer python edition , Then the virtual environment will be created , stay file——settings——project——project interpreter in

show all—— + —— New environment A virtual environment venv —— ok 

  The results of the two methods are the same , Definitely choose the first

install FastAPI Tools for

Method 1 ： stay pyCharm Package management tools can be used in

stay file——settings——project——project interpreter in , Click on +, Search for fastapi, Click on Install

Method 2 ： Common methods , Applicable to all editors

Open the terminal （pyCharm: Terminal）

  Get into venv A virtual environment ——venv\Scripts\activate.bat, Then install fastapi

pip install fastapi[all]

To save memory space , What libraries can be used and what libraries are being installed , Do not install all

pip install fastapi——pip install uvicorn,uvicorn Is the server , The most basic thing is to need these two

pip list View installed Libraries

Use FastAPI

1. Import    from fastapi import FastAPI

2. Initialize object     app=FastAPI()

3.main  function

 Method 1 ：
if __name__ == '__main__':
    uvicorn.run(app)

Method 2 ： At terminal   uvicorn main:app --reload  (main File name )

notes

1. fastapi Document path

http://127.0.0.1:8000/docs

2.   """ The annotation information will be synchronized to the document """

send out post request , use postman test

@app.post("/login")
def login():
    return {"msg":"login success"}

#  Support multiple requests 
@app.api_route("/login",methods=("GET","POST"))
def login():
    return {"msg":"login success"}

obtain URL Parameters

# /city/{city}?q=xx  city Is the path parameter ,？q=xx For query parameters , It is required after operation , Otherwise, it will report a mistake , add option after   Query parameters become optional 
#http://127.0.0.1:8000/city/Beijing?query_string=xx
@app.get('/city/{city}')
def city(city:str, query_string: Optional[str]=None):
    return {'city':city, 'query_string': query_string}

#  test http://127.0.0.1:8000/user/2 , 2 For the parameters passed 
@app.get("/user/{id}")      /  Additive variables 
def user(id):
    return {"id":id}

# http://127.0.0.1:8000/stu?id=8    Query string 
@app.get("/stu")           ?  Additive variables 
def stu(id):
    return {"id":id}

Different method paths can be the same

@app.post('/stu')
def stu():
    return {"hello":"world"}

Request header pass parameters Header

Get the user name and password token, Is stored in the request header , You need to import Header, use token Value to access other interfaces , That is, use the request header to pass parameters

@app.get("/pra")
def pra(id,token=Header(None)):   # Default parameters , The names have to be consistent ,token——postman Inside, too token
    return {"id":id,"token":token}

Request body passing parameters

#  Request body Body, Default parameters , Random names 
@app.post("/login")
def login(a=Body(None)):
    return {"a":a}

json Format transfer data ,Body class

form Transfer data in form format , Import Form class

Ensure that the accepted field name is consistent with the passed field name ,Form The form class needs to be downloaded python-multipart

@app.post("/login")
def login(name=Form(None),age=Form(None)):
    return {"data":{"name":name,"age":age}}

Modify response status code

JSONResponse The format of the returned data is json object

 Import required from fastapi.responses import JSONResponse
# content Returned data   status_code Status code   headers You can add parameters in the request header 
@app.get("/user")
def user():
    return JSONResponse(content={"msg":"get user"},
                        status_code=202,
                        headers={"a":"b"})

 HTMLResponse The way to return data is html page

@app.get("/")
def user():
    html_content = """"
    <html>
    <body><p style="color:red">Hello World</p></body>
    </html>
    """
    return HTMLResponse(content=html_content)

FileResponse The way to return data is by file

@app.get("/avatar")
def user():
    avatar = 'static/mage.jpg'
    return FileResponse(avatar,filename="mage.jpg")

No, filename="mage.jpg" Parameters , The browser directly displays the picture , You have this parameter , The browser will prompt to download the picture

  Need to download a package ：aiofiles—— pip install aiofiles

Return through the template engine HTML page

from fastapi.templating import Jinja2Templates   Common template engine 

install pip install jinja2

The data of pages on the web will change , All you need Request obtain

from fastapi import FastAPI,Request
from fastapi.templating import Jinja2Templates
app = FastAPI()
template = Jinja2Templates("pages")
#  Return through the template engine HTML page , context Parameters cannot be left blank , And inside must be request
@app.get("/")
def user(username,req: Request):
    return template.TemplateResponse("index.html",context={"request":req,"name":username})

username Put the obtained data into the template engine

"name":username—— username It's from the background ,name It's the front end , Background rendering to foreground