Forward slash "/" concatenation for STATIC_ROOT and MEDIA_ROOT (Django)

Question

I found sometimes forward slash "/" is used to concatenate "BASE_DIR" and "static" or "media" for "STATIC_ROOT" and "MEDIA_ROOT" in "settings.py" as shown below:

# "settings.py"
                     # Here
STATIC_ROOT = BASE_DIR / 'static'
                    # Here
MEDIA_ROOT = BASE_DIR / 'media'

So, it's possible to concatenate BASE_DIR which is 'PosixPath' type and 'static' which is 'str' type with forward slash "/".

But when I tried to concatenate 'str' type and 'str' type with "/":

# "settings.py"

STATIC_ROOT = 'abc' / 'static'

I got this error below:

TypeError: unsupported operand type(s) for /: 'str' and 'str'

And for 'int' type and 'str' type with "/":

STATIC_ROOT = 123 / 'static'

I got this error below:

TypeError: unsupported operand type(s) for /: 'int' and 'str'

Then for 'MyClass' type and 'str' type with "/":

# "settings.py"

class MyClass:
    pass

STATIC_ROOT = MyClass() / 'static'

I got this error below:

TypeError: unsupported operand type(s) for /: 'MyClass' and 'str'

So, can we only concatenate 'PosixPath' type and 'str' type with forward slash "/"? Aren't there any other types to concatenate with forward slash "/"?

Answer 1

Django==3.x use pathlib, which allow you to use / to concatenate paths.

Answer 2

If you want to achieve the same behaviour in one of your classes you will have to implement the method __truediv__.

class Thing:
    def __init__(self, name):
        self.name = name

    def __truediv__(self, other):
        return Thing(self.name + other)


thing = Thing('Monty')
other_thing = thing / 'Python'
print(other_thing.name)

This will give you the output MontyPython.

If you want to be able to concatenate not only a Thing instance and a string but two Thing instances you have to check the type of other.

class Thing:
    def __init__(self, name):
        self.name = name

    def __truediv__(self, other):
        if isinstance(other, Thing):
            return Thing(self.name + other.name)
        return Thing(self.name + other)


thing = Thing('Monty')
thing2 = Thing('Python')
other_thing = thing / thing2
print(other_thing.name)