Django/Python Practice Questions
========================

1. Find the most frequent integer in a list, Test list : [3,5,6,3,9,0,3,8,3,1,3]
2. Given two tables:

  ```python
    class Stream(models.Model):
	    name = models.CharField(max_length=100)
	    short_name = models.CharField(max_length=255, null=True, blank=True)

    class Specialization(models.Model):
	    name = models.CharField(max_length=100)
	    stream = models.ForeignKey(Stream, null=True, blank=True)
  ```
  write django query to select all specialization along with stream using select related.
  if stream was a many to many key, how would you you change your query ?
3. Create a method on Stream model which should return only deleted objects (Hint: User model manager)

	```python
	    class Stream(models.Model):
		    name = models.CharField(max_length=100)
		    short_name = models.CharField(max_length=255, null=True, blank=True)
		    deleted = models.BooleanField(default=False)
	```
4. Find the common elements of 2 lists

	```python
	    a = [2,3,4,1,1,3,6]
	    b = [2,8,9,1,3]
	```
	find integers which are in list a but not list b
	do not use loops !

5. Consider the Stream model, create a Form for this model and restrict the user from uploading any images other than PNG, throw a validation error

	```python
	    class Stream(models.Model):
		    name = models.CharField(max_length=100)
		    short_name = models.CharField(max_length=255, null=True, blank=True)
		    icon = models.ImageField(upload_to='img/appicons/', verbose_name = "Stream Icon")
		    deleted = models.BooleanField(default=False)
	```
6. Consider Following models, write django ORM query to get latest activity for each user

	```python
	    class UserProfile(models.Model):
		    name = models.CharField(max_length=100)
		    email = models.EmailField(max_length=255, unique=True)
		    username = models.CharField(max_length=100, unique=True)
		    added_on = models.DateTimeField(auto_now_add=True)
		    updated_on = models.DateTimeField(auto_now=True)

		class UserActivity(models.Model):
		    user = models.ForeignKey(UserProfile)
		    source_url = models.URLField(max_length=400, null=True, blank=True)
		    added_on = models.DateTimeField(auto_now_add=True)
		    updated_on = models.DateTimeField(auto_now=True)
	```

7. Sort this list of tuples by second item in each tuple

	```python
	    awesome_list = [(2,3,1),(6,8,6),(9,1,4),(4,4,0),(2,3,3),(6,2,1)]
	```

8. How do you export data from one database to another having the same model but with no data ? lets say we have a database A with model AppDetails, how do you export data of this model to another database B having same model

9. Difference between StackedInline and TabularInline, if we want to add a model having Manytomany foreign key in django admin, which type of admin model should we use ?

10. Write Django ORM query to find maximum salary of each person having name 'Pinky' or 'Rohit' excluding those which have 0 salary in the folowing model with test data

	```python
		class UserProfile(models.Model):
		    name = models.CharField(max_length=100)
		    email = models.EmailField(max_length=255, unique=True)
		    username = models.CharField(max_length=100, unique=True)
		    added_on = models.DateTimeField(auto_now_add=True)

	    class L2Salary(models.Model):
		    user = models.ForeignKey(UserProfile)
		    salary = models.FloatField()
		    added_on = models.DateTimeField(auto_now_add=True)
	```

	Data in above models:

	```python
		userprofile = [
						  {
						    "added_on": "24-01-01 20:20",
						    "email": "kuldeep@gmail.com",
						    "id": 1,
						    "name": "Kuldeep",
						    "username": "Kully"
						  },
						  {
						    "added_on": "24-01-02 20:20",
						    "email": "mandeep@gmail.com",
						    "id": 2,
						    "name": "Mandeep",
						    "username": "mandy"
						  },
						  {
						    "added_on": "24-02-01 20:20",
						    "email": "rohit@gmail.com",
						    "id": 3,
						    "name": "Rohit",
						    "username": "irohit"
						  },
						  {
						    "added_on": "24-02-01 20:20",
						    "email": "pinky@gmail.com",
						    "id": 4,
						    "name": "Pinky",
						    "username": "pinky"
						  }
						]
		l2salary = [
					  {
					    "added_on": "19-08-08 01:23",
					    "id": 1,
					    "salary": 24000.0,
					    "user_id": 1
					  },
					  {
					    "added_on": "19-08-08 01:23",
					    "id": 2,
					    "salary": 29300.0,
					    "user_id": 1
					  },
					  {
					    "added_on": "19-08-08 01:23",
					    "id": 3,
					    "salary": 21400.0,
					    "user_id": 2
					  },
					  {
					    "added_on": "19-08-08 01:23",
					    "id": 4,
					    "salary": 0.0,
					    "user_id": 3
					  },
					  {
					    "added_on": "19-08-08 01:23",
					    "id": 5,
					    "salary": 12000.0,
					    "user_id": 4
					  },
					  {
					    "added_on": "19-08-08 01:23",
					    "id": 6,
					    "salary": 32000,
					    "user_id": 3
					  },
					  {
					    "added_on": "19-08-08 01:23",
					    "id": 7,
					    "salary": 0.0,
					    "user_id": 3
					  },
					  {
					    "added_on": "19-08-08 01:23",
					    "id": 8,
					    "salary": 23400.0,
					    "user_id": 4
					  }
					]
	```

11. Bonus Question: Write a middleware that restricts only single session per user, if i am logged in from one browser at one place, and if i try to login from any other place using same credentials, it should log out the older session and log me in with current session.