Flask实现REST API之接收POST和GET请求

1、POST和GET的区别与选择

GET and POST are two different types of HTTP requests.

According to Wikipedia:

GET requests a representation of the specified resource. Note that GET should not be used for operations that cause side-effects, such as using it for taking actions in web applications. One reason for this is that GET may be used arbitrarily by robots or crawlers, which should not need to consider the side effects that a request should cause.

and

POST submits data to be processed (e.g., from an HTML form) to the identified resource. The data is included in the body of the request. This may result in the creation of a new resource or the updates of existing resources or both.

So essentially GET is used to retrieve remote data, and POST is used to insert/update remote data.

2、伪代码框架：

from flask import Flask
from flask import requestapp = Flask(__name__)@app.route('/users/<user_id>', methods = ['GET', 'POST', 'DELETE'])
def user(user_id):if request.method == 'GET':"""return the information for <user_id>"""...if request.method == 'POST':"""modify/update the information for <user_id>"""# you can use <user_id>, which is a str but could# changed to be int or whatever you want, along# with your lxml knowledge to make the required# changesdata = request.form # a multidict containing POST data...if request.method == 'DELETE':"""delete user with ID <user_id>"""...else:# POST Error 405 Method Not Allowed...

3、如何接收各种类型参数？

request.data Contains the incoming request data as string in case it came with a mimetype Flask does not handle.

request.args: the key/value pairs in the URL query string
request.form: the key/value pairs in the body, from a HTML post form, or JavaScript request that isn't JSON encoded
request.files: the files in the body, which Flask keeps separate from form. HTML forms must use enctype=multipart/form-data or files will not be uploaded.
request.values: combined args and form, preferring args if keys overlap
request.json: parsed JSON data. The request must have the application/json content type, or use request.get_json(force=True) to ignore the content type.

All of these are MultiDict instances (except for json). You can access values using:

request.form['name']: use indexing if you know the key exists
request.form.get('name'): use get if the key might not exist
request.form.getlist('name'): use getlist if the key is sent multiple times and you want a list of values. get only returns the first value.

参考链接：

python - Flask example with POST - Stack Overflowhttps://stackoverflow.com/questions/22947905/flask-example-with-post python - Get the data received in a Flask request - Stack Overflowhttps://stackoverflow.com/questions/10434599/get-the-data-received-in-a-flask-request