Python – Writing a init function to be used in django model

djangodjango-modelspython

I'm trying to write an __init__ function for one of my models so that I can create an object by doing:

p = User('name','email')

When I write the model, I have:

def __init__(self, name, email, house_id, password):
    models.Model.__init__(self)
    self.name = name
    self.email = email

This works and I can save the object to the database, but when I do User.objects.all(), it doesn't pull anything up unless I take out my __init__ function. Any ideas?

Best Answer

Relying on Django's built-in functionality and passing named parameters would be the simplest way to go.

p = User(name="Fred", email="fred@example.com")

But if you're set on saving some keystrokes, I'd suggest adding a static convenience method to the class instead of messing with the initializer.

# In User class declaration
@classmethod
def create(cls, name, email):
  return cls(name=name, email=email)

# Use it
p = User.create("Fred", "fred@example.com")

Related Solutions

Python – Calling a function of a module by using its name (a string)

Assuming module foo with method bar:

import foo
method_to_call = getattr(foo, 'bar')
result = method_to_call()

You could shorten lines 2 and 3 to:

result = getattr(foo, 'bar')()

if that makes more sense for your use case.

You can use getattr in this fashion on class instance bound methods, module-level methods, class methods... the list goes on.

Python – Using global variables in a function

You can use a global variable within other functions by declaring it as global within each function that assigns a value to it:

globvar = 0

def set_globvar_to_one():
    global globvar    # Needed to modify global copy of globvar
    globvar = 1

def print_globvar():
    print(globvar)     # No need for global declaration to read value of globvar

set_globvar_to_one()
print_globvar()       # Prints 1

Since global variables have a long history of introducing bugs (in every programming language), Python wants to make sure that you understand the risks by forcing you to explicitly use the global keyword.

See other answers if you want to share a global variable across modules.

Best Answer

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Python – Calling a function of a module by using its name (a string)

Python – Using global variables in a function

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