如何为不同的请求添加不同的flask-restful reqparse要求

Question

I'm creating a login endpoint like this for an example:

from flask_restful import reqparse

parser = reqparse.RequestParser()
parser.add_argument('email', help = 'This field cannot be blank', required = True)
parser.add_argument('password', help = 'This field cannot be blank', required = True)

class UserLogin(Resource):
    def post(self):
        data = parser.parse_args()
        current_user = User.find_by_email(data['email'])

        if not current_user:
            return {
            .
            .
            .

The problem is that both arguments now - email and password alike - are mandatory to give. But what if I want to create another endpoint class which would only need one of them as a filled field? Clearly removing the required = True parameter would solve this, but that would break class UserLogin 's logic for validation.

Is there any ready made resource or pattern to do that?

Answer 1

Parser Inheritance

Often you will make a different parser for each resource you write. The problem with this is if parsers have arguments in common. Instead of rewriting arguments you can write a parent parser containing all the shared arguments and then extend the parser with copy() . You can also overwrite any argument in the parent with replace_argument() , or remove it completely with remove_argument() . For example:

from flask_restful import reqparse

parser = reqparse.RequestParser()
parser.add_argument('foo', type=int)

parser_copy = parser.copy()
parser_copy.add_argument('bar', type=int)

# parser_copy has both 'foo' and 'bar'

parser_copy.replace_argument('foo', required=True, location='json')
# 'foo' is now a required str located in json, not an int as defined
#  by original parser

parser_copy.remove_argument('foo')
# parser_copy no longer has 'foo' argument