Category: Python Answers

Sometimes, we want to serialize a model instance in Python Django.

In this article, we’ll look at how to serialize a model instance in Python Django.

How to serialize a model instance in Python Django?

To serialize a model instance in Python Django, we can use the serialize method.

For instance, we write

from django.core import serializers

serialized_obj = serializers.serialize('json', [ obj, ])

to call serializers.serialize with 'json' and the obj object that we want to serialize in a list to serialize obj into a JSON string

Conclusion

To serialize a model instance in Python Django, we can use the serialize method.

To view corresponding SQL query of the Python Django ORM’s queryset, we can use the query property of the query set.

For instance, we write

qs = Model.objects.filter(name='test')
print(qs.query)

to print the SQL query corresponding to the Model.objects.filter(name='test') queryset with

print(qs.query)

Sometimes, we want to fix MySQL "incorrect string value" error when save unicode string in Python Django.

In this article, we’ll look at how to fix MySQL "incorrect string value" error when save unicode string in Python Django.

How to fix MySQL "incorrect string value" error when save unicode string in Python Django?

To fix MySQL "incorrect string value" error when save unicode string in Python Django, we can change some options in the Django app settings.

To fix this, we write

DATABASES = {
    'default': {
        'ENGINE':'django.db.backends.mysql',
        ...
        'OPTIONS': {'charset': 'utf8mb4'},
    }
}

in settings.py.

We can use utf8mb4 characters with MySQL 5.5 or later.

Conclusion

To fix MySQL "incorrect string value" error when save unicode string in Python Django, we can change some options in the Django app settings.

To store a phone number in Python Django models, we can use the phonenumber_field libraru.

To install it, we run

pip install django-phonenumber-field[phonenumbers]

Then in settings.py, we add

INSTALLED_APPS = [
    ...
    'phonenumber_field',
    ...
]

to add 'phonenumber_field' into INSTALLED_APPS.

And then in our model, we add

from phonenumber_field.modelfields import PhoneNumberField

class Client(models.Model, Importable):
    phone = PhoneNumberField(null=False, blank=False, unique=True)

to add the phone PhoneNumberField to add a phone number field.

Then we create a form with

from phonenumber_field.formfields import PhoneNumberField
class ClientForm(forms.Form):
    phone = PhoneNumberField()

Sometimes, we want to convert a string to int in a Python Django template.

In this article, we’ll look at how to convert a string to int in a Python Django template.

How to convert a string to int in a Python Django template?

To convert a string to int in a Python Django template, we can use the add filter.

For instance, we write

{% for item in numItems|add:"0" %}

to use the add filter to add '0' to the item value to convert the item string to an int.

Conclusion

To convert a string to int in a Python Django template, we can use the add filter.