Flask Returns empty json - python

Trying to build a simple Flask app from a tutorial.
At this stage, trying to initiate a successful request from the console that posts new data in my database. I'm running my server in one window via app.py then initiating requests in a console window like this:
requests.post("http://localhost:5000/todo", json={"Title":"my first todo", "Description":"my first todo"})
Expecting to see that output rendered when I visit http://localhost:5000/todo. The server shows a code 200, but when I access the site the json is empty: []
app.py:
from flask import Flask, request, jsonify
from models import Schema
from service import ToDoService
import json
app = Flask(__name__)
#app.route("/todo", methods=["POST"])
def create_todo():
return jsonify(ToDoService().create(request.get_json()))
#app.route("/todo", methods=["GET"])
def list_todo():
return jsonify(ToDoService().list())
if __name__ == "__main__":
Schema()
app.run(debug=True)
models.py:
import sqlite3
class Schema:
def __init__(self):
self.conn = sqlite3.connect('todo.db')
self.create_user_table()
self.create_to_do_table()
def create_to_do_table(self):
class ToDoModel:
global TABLENAME
TABLENAME = "Todo"
def __init__(self):
self.conn = sqlite3.connect('todo.db')
def get_by_id(self, _id):
where_clause = f"AND id={_id}"
return self.list_items(where_clause)
def create(self, text, description):
query = f'insert into {TABLENAME} ' \
f'(Title, Description) ' \
f'values ("{text}","{description}")'
result = self.conn.execute(query)
return self.get_by_id(result.lastrowid)
def select(self, text, description):
query = f'values ("{text}","{description}")'
result = self.conn.execute(query)
return result
def list_items(self, where_clause=""):
query = f"SELECT id, Title, Description, DueDate, _is_done " \
f"from {TABLENAME} WHERE _is_deleted != {1} " + where_clause
#print (query)
result_set = self.conn.execute(query).fetchall()
result = [{column: row[i]
for i, column in enumerate(result_set[0].keys())}
for row in result_set]
return result
service.py:
from models import ToDoModel
class ToDoService:
def __init__(self):
self.model = ToDoModel()
def create(self, params):
result = self.model.create(params["Title"], params["Description"])
return result
def update(self, item_id, params):
return self.model.update(item_id, params)
def list(self):
response = self.model.list_items()
return response

Related

internal server error after submitting a form flask,sqlite3 [duplicate]

This question already has answers here:
Flask view return error "View function did not return a response"
(3 answers)
Closed last year.
I inserted new record from the form, the data will be successfully added into database, but it will show an error page "INTERNAL SERVER ERROR", if I manually back to my form page and refresh i can see the inserted data, but i want it refresh it self and don't show the error page, how to do that?
from flask import Flask, render_template, request
import sqlite3
app = Flask(__name__)
db_name = 'crm.db'
#app.route('/')
def index():
title = "主页"
return render_template("index.html", title = title)
#app.route('/company', methods = ['POST','GET'])
def company():
if request.method == 'GET':
title = "公司"
company_db = query_company()
return render_template("company.html", title = title, company_db = company_db)
else:
insert_company()
def query_company():
connection = sqlite3.connect(db_name)
c = connection.cursor()
c.execute("""SELECT * FROM company""")
company_db = c.fetchall()
return company_db
def insert_company():
connection = sqlite3.connect(db_name)
c = connection.cursor()
query = 'INSERT INTO company(company_full_name, company_short_name) VALUES(?,?)'
cfn = request.form.get("cfn")
csn = request.form.get("csn")
company_info = (cfn,csn)
c.execute(query, company_info)
connection.commit()
connection.close()
if __name__ == '__main__':
app.run(debug = True)
Change the company function to ...
def company():
if request.method == 'POST':
insert_company()
title = "公司"
company_db = query_company()
return render_template("company.html", title = title, company_db = company_db)
This way the new data will first be inserted and then all rows will be automatically refreshed

Pass username to flask and retrieve the data using sqlite3

So I have just started studying on flask and am just moving to database with flask. I have a database "testdatabase.db" with a table named "Students". What I want to do is. When i pass a username onto the url I need the details of the that specific row.
Here is my python code
from flask import Flask, render_template, request
import sqlite3
conn = sqlite3.connect('testdatabase.db')
c = conn.cursor()
app = Flask(__name__)
#app.route("/students/<name>")
def students(name):
return jam()
def jam():
c.execute("select * from students where name = '" + name + "'")
print(c.fetchall())
conn.close()
if __name__ == "__main__":
app.run(debug=True)
The error being shown is that name 'name' is not defined. How do I define the name to be passed to the url?
Name is being passed correctly to the url
#app.route("/students/<name>")
def students(name):
return jam()
Your only problem is that you are not passing it to the jam function
solution
#app.route("/students/<name>")
def students(name):
return jam(name)
def jam(name):
c.execute("select * from students where name = '" + name + "'")
print(c.fetchall())
conn.close()
# Return the data jsonfied.
There is no variable 'name' in jam, try:
from flask import Flask, render_template, request
import sqlite3
conn = sqlite3.connect('testdatabase.db')
c = conn.cursor()
app = Flask(__name__)
#app.route("/students/<name>")
def students(name):
return jam(name)
def jam(name):
c.execute("select * from students where name = '" + name + "'")
print(c.fetchall())
conn.close()
if __name__ == "__main__":
app.run(debug=True)

Error 500 when running python flask application with xampp

I am trying to run a flask application with xampp but I can't run it on the web server.
I have added .py to Addhandler in /opt/lampp/etc/httpd.conf and at the top of all my scripts I added this: #!/usr/bin/python
#!/usr/bin/python
import sqlite3, os, hashlib
from flask import Flask, jsonify, render_template, request, g
app = Flask(__name__)
app.database = "sample.db"
#app.route('/')
def index():
return render_template('login.html')
#API routes
#app.route('/api/v1.0/storeLoginAPI/', methods=['POST'])
def loginAPI():
if request.method == 'POST':
uname,pword = (request.json['username'],request.json['password'])
g.db = connect_db()
cur = g.db.execute("SELECT * FROM employees WHERE username = '%s' AND password = '%s'" %(uname,pword))
if cur.fetchone():
result = {'status': 'success'}
else:
result = {'status': 'fail'}
g.db.close()
return jsonify(result)
#app.route('/api/v1.0/storeAPI', methods=['GET', 'POST'])
def storeapi():
if request.method == 'GET':
g.db = connect_db()
curs = g.db.execute("SELECT * FROM shop_items")
cur2 = g.db.execute("SELECT * FROM employees")
items = [{'items':[dict(name=row[0], quantity=row[1], price=row[2]) for row in curs.fetchall()]}]
empls = [{'employees':[dict(username=row[0], password=row[1]) for row in cur2.fetchall()]}]
g.db.close()
return jsonify(items+empls)
elif request.method == 'POST':
g.db = connect_db()
name,quan,price = (request.json['name'],request.json['quantity'],request.json['price'])
curs = g.db.execute("""INSERT INTO shop_items(name, quantitiy, price) VALUES(?,?,?)""", (name, quan, price))
g.db.commit()
g.db.close()
return jsonify({'status':'OK','name':name,'quantity':quan,'price':price})
#app.route('/api/v1.0/storeAPI/<item>', methods=['GET'])
def searchAPI(item):
g.db = connect_db()
#curs = g.db.execute("SELECT * FROM shop_items WHERE name=?", item) #The safe way to actually get data from db
curs = g.db.execute("SELECT * FROM shop_items WHERE name = '%s'" %item)
results = [dict(name=row[0], quantity=row[1], price=row[2]) for row in curs.fetchall()]
g.db.close()
return jsonify(results)
#app.errorhandler(404)
def page_not_found_error(error):
return render_template('error.html', error=error)
#app.errorhandler(500)
def internal_server_error(error):
return render_template('error.html', error=error)
def connect_db():
return sqlite3.connect(app.database)
# Create password hashes
def hash_pass(passw):
m = hashlib.md5()
m.update(passw)
return m.hexdigest()
if __name__ == "__main__":
#create database if it doesn't exist yet
if not os.path.exists(app.database):
with sqlite3.connect(app.database) as connection:
c = connection.cursor()
c.execute("""CREATE TABLE shop_items(name TEXT, quantitiy TEXT, price TEXT)""")
c.execute("""CREATE TABLE employees(username TEXT, password TEXT)""")
c.execute('INSERT INTO shop_items VALUES("water", "40", "100")')
c.execute('INSERT INTO shop_items VALUES("juice", "40", "110")')
c.execute('INSERT INTO shop_items VALUES("candy", "100", "10")')
c.execute('INSERT INTO employees VALUES("itsjasonh", "{}")'.format(hash_pass("badword")))
c.execute('INSERT INTO employees VALUES("theeguy9", "{}")'.format(hash_pass("badpassword")))
c.execute('INSERT INTO employees VALUES("newguy29", "{}")'.format(hash_pass("pass123")))
connection.commit()
connection.close()
app.run()
When I run my apache server and try to access localhost/sql.py I get an "Error message:
End of script output before headers: sql.py

OperationalError: no such table: books on python anywhere

I have a file structure on python anywhere as :
flaskhost(folder) which contains :
app.py
books.db
app.py contains -:
import flask
from flask import request, jsonify
import sqlite3
app = flask.Flask(__name__)
app.config["DEBUG"] = True
def dict_factory(cursor, row):
d = {}
for idx, col in enumerate(cursor.description):
d[col[0]] = row[idx]
return d
#app.route('/', methods=['GET'])
def home():
return '''<h1>Distant Reading Archive</h1>
<p>A prototype API for distant reading of science fiction novels.</p>'''
#app.route('/api/v1/resources/books/all', methods=['GET'])
def api_all():
conn = sqlite3.connect('books.db')
conn.row_factory = dict_factory
cur = conn.cursor()
all_books = cur.execute('SELECT * FROM books;').fetchall()
return jsonify(all_books)
#app.errorhandler(404)
def page_not_found(e):
return "<h1>404</h1><p>The resource could not be found.</p>", 404
#app.route('/api/v1/resources/books', methods=['GET'])
def api_filter():
query_parameters = request.args
id = query_parameters.get('id')
published = query_parameters.get('published')
author = query_parameters.get('author')
query = "SELECT * FROM books WHERE"
to_filter = []
if id:
query += ' id=? AND'
to_filter.append(id)
if published:
query += ' published=? AND'
to_filter.append(published)
if author:
query += ' author=? AND'
to_filter.append(author)
if not (id or published or author):
return page_not_found(404)
query = query[:-4] + ';'
conn = sqlite3.connect('books.db')
conn.row_factory = dict_factory
cur = conn.cursor()
results = cur.execute(query, to_filter).fetchall()
return jsonify(results)
if __name__ == '__main__':
app.run()
I am trying to follow this tutorial
https://programminghistorian.org/en/lessons/creating-apis-with-python-and-flask
my site is hosted at :
http://vivanks.pythonanywhere.com
But when I call api by
http://127.0.0.1:5000/api/v1/resources/books?author=Connie+Willis
It show me error :
sqlite3.OperationalError: no such table: books
Any help how to fix this and host app on pythonanywhere.com ?
P.S On my local machine it's working perfectly fine
On Pythonanywnere, When pointing to content other than templates or static files (stored in their own proper directories, accessible by flask), you have to provide the full path:
conn = sqlite3.connect('/home/your_username/flaskhost/books.db')

sqlite on dreamhost via flask/JSON - getting 404s

I've got a flask app that queries a sqlite database and returns a list to html via jsonify. It works fine on localhost, but I've uploaded to dreamhost and am getting 404s for the jsonified lists. I can't tell whether it is an issue with flask communicating with my sqlite database, flask, or with json.
Here is the flask app:
#!/usr/bin/python
import sqlite3 as sqlite
import json
from flask import Flask, g, jsonify, make_response, render_template
DEBUG = True
DATABASE = './whdt_combined.db'
#setup flask application
app = Flask(__name__)
app.config.from_object(__name__)
##########################
### DATABASE STUFF #######
##########################
#connect to the database
def connect_db():
rv = sqlite.connect(app.config['DATABASE'])
rv.row_factory = dict_factory
return rv
#function for making rows nice
def dict_factory(cursor, row):
d = {}
for idx, col in enumerate(cursor.description):
d[col[0]] = row[idx]
return d
#open new db connection if ones hasn't been opened
def get_db():
if not hasattr(g, 'sqlite_db'):
g.sqlite_db = connect_db()
return g.sqlite_db
#when application stops, close db connection
#app.teardown_appcontext
def close_db(error):
if hasattr(g, 'sqlite_db'):
g.sqlite_db.close()
#easy function to nicely query the db
def query_db(query, args=(), one =False):
cur = get_db().execute(query, args)
rv = cur.fetchall()
cur.close()
return (rv[0] if rv else None) if one else rv
##########################
### APPLICATION ##########
##########################
#app.route('/')
def index():
return render_template('index.html')
#app.route('/<data1>/<data2>/<region>/<year>/1/')
def datafunction1(data1, data2, region, year):
data = []
for row in query_db('SELECT ccode, country, year, region, ' + data1 + ' FROM whdt WHERE year = ' + year + ' AND region = "' + region + '" AND ' + data1 + ' != "" AND ' + data1 + ' > 0 AND ' + data1 + ' < 100 ORDER BY ' + data1 + ' DESC'):
countrywhole = {
'country' :row['country'],
'ccode':row['ccode'],
'year':row['year'],
'region':row['region'],
data1:row[data1]
}
data.append(countrywhole)
return jsonify( { 'data': data } )
if __name__ == '__main__':
app.run()
And here is my folder setup:
/home/user/mydomain.com/myapp/whdt_combined.db
/home/user/mydomain.com/myapp/myapp.py
/home/user/mydomain.com/myapp/__init__.py
/home/user/mydomain.com/myapp/templates/index.html
/home/user/mydomain.com/myapp/static/a couple of css and js files
Flask is not having trouble rendering index.html. Part of the issue is I don't know how to debug through dreamhost. I'm fairly new to this stuff so I'm sorry if I am missing something obvious or otherwise clearly don't know what I'm talking about. Please let me know if I should be providing other important information here. And thanks in advance for your help!

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