Myujth

I am not sure why I am getting this TypeError:

File "C:/Users/PycharmProjects/REST/app.py", line 30, in
valid_book_object
if ("isbn" in book and "name" in book and "price" in book):
TypeError: argument of type 'NoneType' is not iterable
127.0.0.1 - - [12/Nov/2018 14:22:29] "POST /books HTTP/1.1" 500 -

Code:

from flask import Flask, jsonify, request
from test import *
app=Flask(__name__)

books=[
 'name': 'M',
 'price': 6.75,
 'isbn':123
 ,
 'name': 'G',
 'price': 7.75,
 'isbn':456
 ,

]


#GET /store
@app.route('/books') #first endpoint
def get_books():
 return jsonify('books': books)

# POST /books
#'name': 'F',
 #'price': 7.00,
 #'isbn': 789
 #,

def valid_book_object(book):
 if ("isbn" in book and "name" in book and "price" in book):
 return True
 print("true")
 else:
 return False
 print("false")


@app.route('/books', methods=['POST'])
def add_book():
 #return jsonify(request.get_json())
 request_data=request.get_json()
 if(valid_book_object(request_data)):
 books.insert(0, request_data)
 return "True"
 else:
 return "False"


#GET /books/456
@app.route('/books/<int:isbn>') #second endpoint
def get_book_by_isbn(isbn):
 return_value=
 for book in books:
 if book["isbn"]==isbn:
 return_value=
 'name': book["name"],
 'price':book["price"]
 
 return jsonify(return_value)



app.run(port=5000)

You are not sending JSON data to /books route using POST method.

I tried your solution with postman and it worked. Also, if you want to use some route for GET and POST, don't split them. Use methods=['GET', 'POST']. Here is your code reformatted with PEP 8 standard:

from flask import Flask, jsonify, request

app = Flask(__name__)

books = [
 'name': 'M',
 'price': 6.75,
 'isbn': 123
 ,
 'name': 'G',
 'price': 7.75,
 'isbn': 456
 
]

# POST /books
# 
# "name": "F",
# "price": 7.00,
# "isbn": 789
# 


def valid_book_object(book):
 if "isbn" in book and "name" in book and "price" in book:
 return True
 else:
 return False


@app.route('/books', methods=['GET', 'POST'])
def add_book():
 # If request is GET, just return JSON data of books.
 if request.method == 'GET':
 return jsonify('books': books)
 else:
 # This is part if it is POST request
 request_data = request.get_json()
 if valid_book_object(request_data):
 books.insert(0, request_data)
 return "True"
 else:
 return "False"


# GET /books/456
@app.route('/books/<int:isbn>') # second endpoint
def get_book_by_isbn(isbn):
 return_value = 
 for book in books:
 if book["isbn"] == isbn:
 return_value = 
 'name': book["name"],
 'price': book["price"]
 
 return jsonify(return_value)
 return 'No book with isbn value'.format(isbn)


if __name__ == '__main__':
 app.run(port=5000)

And here is the output from postman (you can see True at the bottom, that is what you return if POST was successful):

If you use postman, be sure to select application/json content-type.

If you are using JQuery ajax method, please read this answer. But anyway, here is using JQuery (tested):

data = JSON.stringify(
 name: "F",
 price: 7.00,
 isbn: 789
);
$.ajax(
 url: '/books',
 type: "POST",
 data: data,
 contentType: "application/json",
 dataType: "json",
 success: function()
 console.log('Post executed successfully');
 
)