How to get native type of a model in django

Question

I need to dynamically inspect the python types of all the fields within my models in an app, that is, given that I have:

class MyModel(model.Model):
    field1 = model.CharField(max_length=20)
    field2 = modelf.IntegerField()
    ...
    fieldn = models.BooleanField()

I need to accomplish something like:

>>> for field in MyModel._meta.fields:
•••     field.type
•••
<type 'str'>
<type 'int'>
...

obviously field.type is something that does not exist, but I need to retrieve the built-in type the model is supposed to accept when the model is created/updated. ForeignKeys and M2M are a special case that can be ignored for this question.

Thanks for any help.

Answer 1

Sorry, Field s do not contain such information. The to_python method is used to convert values into the expected Python data type, and it's free to return whatever it likes.

You can build a type map yourself, obviously limited to field types you know about:

FIELD_PYTHON_TYPES = {
    'AutoField': int,
    'BooleanField': bool,
    'CharField': unicode,
    'DateField': datetime.date,
    'DateTimeField': datetime.datetime,
    'DecimalField': decimal.Decimal,
    'FloatField': float,
    'IntegerField': int,
    'BigIntegerField': int,
     ... # etc.
}

and look up types from it with get_internal_type :

for field in MyModel._meta.fields:
    FIELD_PYTHON_TYPES[field.get_internal_type()]

But even, for example, built-in NullBooleanField can use two types ( bool and NoneType ), so it's far from a general solution.