model.py

class Photo:
    def __init__(self):
        self.width = 0
        self.height = 0
        self.code = ''
        self.is_ad = False
        self.likes_count = 0
        self.viewer_has_liked = False
        self.is_video = False
        self.id = 0
        self.display_src = ''
        self.location = 'null'
        self.owner_id = 'null'
        self.caption = 'null'
        self.owner_username = 'null'

    def from_json(self, json_node):
        if (json_node == None):
            return None

        if (not json_node.get('id', None)):
            return None

        # This is required.
        self.id = json_node.get('id')

        dimensions = json_node.get('dimensions', None)
        if (dimensions):
            self.width = dimensions.get('width', 0)
            self.height = dimensions.get('height', 0)

        self.code = json_node.get('shortcode', '')
        self.is_ad = json_node.get('is_ad', False)
        if (json_node.get('likes', None)):
            self.likes_count = json_node['likes']['count']
            self.viewer_has_liked = json_node['likes'].get('viewer_has_liked', False)
        self.is_video = json_node.get('is_video', False)
        self.display_src = json_node['display_url']
        if (json_node.get('location')):
            self.location = json_node.get('location').get('name', 'null')
        self.caption = json_node.get('caption', 'null')
        self.owner_id = json_node['owner'].get('id', 'null')
        self.owner_username = json_node['owner'].get('username', 'null')

        return self


class User:
    def __init__(self):
        self.id = 0
        self.username = 'null'
        self.has_blocked_viewer = False
        self.follows_count = 0
        self.followed_by_count = 0
        self.external_url = 'null'
        self.follows_viewer = False
        self.profile_pic_url = 'null'
        self.is_private = False
        self.full_name = 'null'
        self.posts_count = 0
        self.blocked_by_viewer = False
        self.followed_by_viewer = False
        self.is_verified = False
        self.biography = 'null'

    def from_json(self, json_node):
        if (json_node == None):
            return None
        self.username = json_node.get('username', 'null')
        self.has_blocked_viewer = json_node.get('has_blocked_viewer', False)
        self.follows_count = json_node['follows'].get('count', 0)
        self.followed_by_count = json_node['followed_by'].get('count', 0)
        self.external_url = json_node.get('external_url', 'null')
        self.follows_viewer = json_node.get('follows_viewer', False)
        self.profile_pic_url = json_node.get('profile_pic_url', 'null')
        self.is_private = json_node.get('is_private', False)
        self.full_name = json_node.get('full_name', 'null')
        self.posts_count = json_node['media'].get('count', 0)
        self.blocked_by_viewer = json_node.get('blocked_by_viewer', False)
        self.followed_by_viewer = json_node.get('follows_viewer', False)
        self.is_verified = json_node.get('is_verified', False)
        self.id = json_node.get('id', 'null')
        bio = json_node.get('biography', 'null')
        self.biography = 'null' if bio == None else bio.replace('\'', '')

        return self

class Activity:
    def __init__(self):
        self.timestamp = 'null'
        self.user_id = 0
        self.type = 0

    def from_json(self, json_node):
        self.timestamp = json_node.get('timestamp', 'null')
        self.type = json_node.get('type', 0)
        self.user_id = json_node['user'].get('pk', 0)
        return self