Django best practice - compare users

Question

I'm working on a small project and I have a user profile page.

This page has a variable called user. This variable contains the user object of the current profile page. The logged in user object is accessible with request.user

If you just print the user object it will return the username because the model returns this in the __str__ function

What is the best way to compare if the user profile belongs to the current user?

I could just write

if user == request.user

But what if django changes the return value of the __str__ function?

or I could write

if user.username == request.user.username

or

if user.id == request.user.id

Answer 1

if user == request.user: is the correct way. Comparison is based on database primary keys, not on string representations. Django docs: https://docs.djangoproject.com/en/2.0/topics/db/queries/#comparing-objects

Answer 2

Roman Miroshnychenko answered the question already, just a small addendum:

Looks like the question originated because you assumed that == comparison would internally call the __str__ function. This is not the case.

The __str__ method is sometimes called implicitly, but only in well defined places, like:

• by the print function in print(obj)
• by string formatting in '{0}'.format(obj) or f'{obj}' or '%s' % obj

There's also the __repr__ method that is called implicitly in other places, such as after each value in Python interactive shell:

>>> a = SomeObject()
>>> a
<__main__.SomeObject object at 0x7f5f218889e8>

However the == operator doesn't touch any of that and calls the __eq__ method instead. Hope that helps!