I want visitors of my page to be able to create entries without registering first. When they register later I want everything they have created within that session to belong to their user account.
To achieve that I just want to create blank users with random usernames when entries from non users are made.
What is the most elegant way to create a unique username randomly avoiding any collision?
Should I just make a while loop that generates usernames and tries to save them to the db with a break upon success or is there a better way?
Most scripts I've seen just create a random string, but that has the danger of a collision. Is there any Django function that creates random usernames based on which usernames are already taken?
No, django doesn't have such function. So you have to check for the existence of the generated username in the loop.
I created a mixin that creates a random username based on firstname, lastname and makes sure this username doesnt already exist in db User model:
random_username_mixin.py
import random
import string
from core.models import CustomUser
class RandomUsernameMixin:
"""
using firstname & lastname
create a random username (all lower case)
that doesnt already exist in db
"""
num_of_random_letters = 3
num_of_random_numbers = 2
user_model = CustomUser
def get_username(self, firstname=None, lastname=None):
username = ''
if firstname and lastname \
and firstname != '' and lastname != '':
username = firstname[0] + lastname[0]
while True:
random_letters = string.ascii_lowercase
random_numbers = string.digits
username += self.get_random_char(
random_letters, self.num_of_random_letters
)
username += self.get_random_char(
random_numbers, self.num_of_random_numbers
)
if self.username_exist_in_db(username) is False:
return username
def username_exist_in_db(self, username):
"""
:return: True if username already exist in db
else False
"""
q = self.user_model.objects.filter(username=username)
return q.exists()
def get_random_char(self, ip_str, n):
return (''.join(
random.choice(ip_str)
for i in range(n)
))
Following is the testing code. It tests the above code:
test_random_username_mixin.py
from django.test import TestCase
from miscellaneous.mixins.random_username_mixin import RandomUsernameMixin
class TestRandomUsernameMixin(RandomUsernameMixin,
TestCase):
def test_username_with_fn_ln(self):
fn = 'aseem'
ln = 'hegshetye'
username = self.get_username(
firstname=fn, lastname=ln
)
len_of_initials = 2
len_of_username = self.num_of_random_numbers + \
self.num_of_random_letters + \
len_of_initials
self.assertEqual(len(username), len_of_username)
print(username)
def test_username_without_fn_ln(self):
username = self.get_username()
len_of_initials = 0
len_of_username = self.num_of_random_numbers + \
self.num_of_random_letters + \
len_of_initials
self.assertEqual(len(username), len_of_username)
print(username)
Related
I want to create some users just to populate my database, so using decorators I created a method inside a class for it. I returned the results into a list and used the information without a problem. But after a while I thought that once I was working with classes wouldn't be dumb to use lists? I feel that I am kind of moving backwards since, at least in my understanding, it might be possible to access those values directly.. But the truth is I struggled on attempting to instantiate dynamically and access those instances. So, how could I do that properly? Here is the code I wrote in the first attempt:
class User:
def __init__(self, user_name, password, email, i=0):
self.user_name = user_name
self.password = password
self.email = email
#classmethod
def from_generate(cls, amount):
user_name = 'user' + str(amount)
password = 'password000.' + str(amount)
email = 'user' + str(amount) + "#whatever.com"
return cls(user_name, password, email)
in another file:
def user_generator(user_qty=0):
user_list = []
for i in range(1, user_qty + 1):
# call the class method to generate users
instance = User.from_generate(i)
user_list.append(instance)
return(user_list)
users = user_generator(5)
if __name__ == "__user_generator__":
user_generator()
I am trying to simulate a system access portal using classes and methods. I want to be able to ask the user for their username using input(), check if that input is an object of class User and if so, check if the password is correct for the username. When I use instance of it is returning false. How can I modify this to work?
class User():
def __init__(self, username, password):
self.username = username
self.password = password
def change_pw(self, new_password):
self.password = new_password
jshannon = User("jshannon","AbC!23")
print(jshannon.username)
print(jshannon.password)
jshannon.change_pw("(i*u&y1")
print(jshannon.password)
input_user = input("What is your username? ")
print(isinstance(input_user, User))
User inputs are strings. Always. Period. So you can not "check if that input is an object of class User" - it will never be.
The solution here is to maintain a collection of User instances, and use the input string to search for a matching user.
class UsersCollection(object):
def __init__(self):
# we store users in a dict, with user.usernale as key
self._users = {}
def add(self, user):
if user.username in self._users:
raise ValueError("username '{}' already in used".format(user.username))
self._users[user.username] = user
def get(self, username):
return self._users.get(username)
users = UsersCollection()
users.add(User("jshannon","AbC!23"))
input_user = input("What is your username? ").strip()
userfound = users.get(input_user)
if userfound:
# you can do something with your user
else:
print("sorry, we don't know you")
Note that this is only suitable as a toy project of course.
If you are using Python 3.x (which I'm going to assume), input returns a string so isinstance(input_user, User) will always be False.
You will need to keep track of all User objects created and search for the object with the inputted name.
There are several different ways to do that. I'm going to assume that usernames are unique so I will use them in a shared set:
class User:
users = set()
def __init__(self, username, password):
self.username = username
self.password = password
self.users.add(username)
def change_pw(self, new_password):
self.password = new_password
jshannon = User("jshannon", "AbC!23")
print(jshannon.username)
print(jshannon.password)
jshannon.change_pw("(i*u&y1")
print(jshannon.password)
input_user = input("What is your username? ")
print(input_user in User.users)
# will output True if input_user is jshannon, otherwise False
Note that this is just an example, and it is not bullet-proof nor the best design (one may argue if the users set even belongs to the User class Hint: probably not). If an object's username changes after the initialization the set will not be updated and you may get wrong results. This particular problem can be solved by changing self.username to a property but I suppose that is out of scope of this Q&A.
I am not sure if this is what you want to do but you cant try this
add a list to your class list_of_usernames = []
and then in __init__() append username to the list_of_usernames and at the end
print(input_user in User.list_of_usernames)
so your code will look like this
class User():
list_of_usernames = []
def __init__(self, username, password):
self.username = username
self.password = password
self.list_of_usernames.append(username)
def change_pw(self, new_password):
self.password = new_password
jshannon = User("jshannon","AbC!23")
print(jshannon.username)
print(jshannon.password)
jshannon.change_pw("(i*u&y1")
print(jshannon.password)
input_user = input("What is your username? ")
print(input_user in User.list_of_usernames)
I was wondering if this would be possible, to save a dictionary item to a variable. So simply this is what I am doing. I am saving this item to a dictionary:
accounts{}
def accountcreator():
newusername = raw_input()
newpassword = raw_input()
UUID = 0
UUID += 1
accounts[newusername] = {newpassword:UUID}
Now basically I will be looping through the newusernames in a separate function:
def accounts():
username = raw_input()
for usernames in accounts:
if usernames == username:
#Not sure what to do from here on out
else:
accounts()
This is where I get confused. So if the username input equals a newusername in the accounts dictionary it will contiune on. I want it to save that newusernames password and UUID (the {newpassword:UUID} part) to a variable. So basically if the newusername equals the username input it will save the rest of thats informations (the {newpassword:UUID}) to a variable. So in the end the variable lets say accountinfo = {newpassword:UUID}. Thank you, I hope that makes sense.
There are a couple of errors in your code. First, probably a typo:
accounts = {}
Next, when you create the code, you are always resetting UUID to 0, making the increment a little pointless. Initialize UUID outside the function, like you do with accounts:
UUID = 0
def accountcreator():
newusername = raw_input()
newpassword = raw_input()
UUID += 1
accounts[newusername] = {newpassword:UUID}
Third, I'm not sure why you are mapping the password to the UUID. Likely, you want two separate fields in the user dictionary to store both:
accounts[newusername] = { 'password': newpassword, 'UUID': UUID }
Finally, the whole point of using a dictionary to map user names to information is that you don't need to iterate over the entire dictionary; you just index the dictionary with the user name. You do have to take care that you don't try to access a nonexistent key, though.
# Use a different name; accounts is already a dictionary
def get_account():
username = raw_input()
if username in accounts:
return accounts[username]
else:
print("No account for {0}".format(username))
I'm trying to make a function that checks if the user is logged in. I've placed the function outside of the mainpage class and it gives no errors until I try to use it insie the def get(self) within the MainPage class. The function looks like this:
def LoginCheck():
username = self.request.cookies.get('username')
password = self.request.cookies.get('password')
if username and password:
checkq = db.GqlQuery("SELECT * FROM Users WHERE username = :1 AND password = :2", username, password)
checkresult = checkq.get()
if checkresult is None:
self.redirect("/wrong")
else:
self.redirect("/wrong2")
and When I try to use it it returns:
line 14, in LoginCheck
username = self.request.cookies.get('username')
NameError: global name 'self' is not defined
What am I doing wrong?
You'll have to add "self" to your function definition. See section 9.3.2 of python's tutorial.
def LoginCheck(self):
username = self.request.cookies.get('username')
password = self.request.cookies.get('password')
if username and password:
checkq = db.GqlQuery("SELECT * FROM Users WHERE username = :1 AND password = :2", username, password)
checkresult = checkq.get()
if checkresult is None:
self.redirect("/wrong")
else:
self.redirect("/wrong2")
(1) is this way : http://code.google.com/intl/en/appengine/articles/djangoforms.html
(2) is write by self :
#/usr/bin/env python2.5
#----------------------------
# Datastore models for user & signup
#----------------------------
from base64 import b64encode as b64
from hashlib import md5, sha256
from random import randint
from time import time
from google.appengine.ext import db
N_SALT = 8 # length of the password salt
def salt_n_hash(password, salt=None):
"""
Generate a salt and return in base64 encoding the hash of the
password with the salt and the character '$' prepended to it.
"""
salt = salt or b64( ''.join(chr(randint(0, 0xff)) for _ in range(N_SALT)) )
return salt + '$' + b64( sha256(salt+password.encode("ascii")).digest() )
class User(db.Model):
nickname = db.StringProperty(required=True)
email = db.EmailProperty(required=True)
pwd = db.StringProperty(required=True)
suspended = db.BooleanProperty(default=True)
#classmethod
def authenticate(klass, nickname, password):
"""Return an User() entity instance if password is correct"""
user = klass.get_by_key_name(nickname)
if user:
n_salt = user.pwd.index('$')
if user.pwd == salt_n_hash(password, salt=user.pwd[:n_salt]):
return user
def __eq__(self, other):
return self.nickname == other.nickname
def signup_id(nickname):
return md5( nickname + repr(time()) ).hexdigest()
class UserSignup(db.Model):
user = db.ReferenceProperty(User, required=True)
date = db.DateProperty(auto_now_add=True)
which way is better ,
or did you have better way to do this , ex: a simply form Validation framework,
thanks
If you're using Django, djangoforms is definitely the way to go. If tipfy or other light-weight frameworks, try wtforms (it's also in the tipfy source tree).