base_model.py

#!/usr/bin/python3
"""This module defines a base class for all models in our hbnb clone"""
import uuid
from datetime import datetime
from sqlalchemy import Column, Integer, String, DateTime
from sqlalchemy.ext.declarative import declarative_base
from os import getenv

storage_type = getenv("HBNB_TYPE_STORAGE")

Base = declarative_base()


class BaseModel:
    """A base class for all hbnb models"""

    id = Column(String(60), unique=True, nullable=False, primary_key=True)
    created_at = Column(DateTime, nullable=False, default=datetime.utcnow())
    updated_at = Column(DateTime, nullable=True, default=datetime.utcnow())

    def __init__(self, *args, **kwargs):
        """Instantiation of base model class
        Args:
            args: it won't be used
            kwargs: arguments for the constructor of the BaseModel
        Attributes:
            id: unique id generated
            created_at: creation date
            updated_at: updated date
        """
        if kwargs:
            for key, value in kwargs.items():
                if key == "created_at" or key == "updated_at":
                    value = datetime.strptime(value, "%Y-%m-%dT%H:%M:%S.%f")
                if key != "__class__":
                    setattr(self, key, value)
            if "id" not in kwargs:
                self.id = str(uuid.uuid4())
            if "created_at" not in kwargs:
                self.created_at = datetime.now()
            if "updated_at" not in kwargs:
                self.updated_at = datetime.now()
        else:
            self.id = str(uuid.uuid4())
            self.created_at = self.updated_at = datetime.now()

    def __str__(self):
        """Returns a string representation of the instance"""
        cls = (str(type(self)).split(".")[-1]).split("'")[0]
        return "[{}] ({}) {}".format(cls, self.id, self.to_dict())

    def save(self):
        """Updates updated_at with current time when instance is changed"""
        from models import storage

        self.updated_at = datetime.now()
        storage.new(self)
        storage.save()

    def delete(self):
        """
        Delete the current instance from the storage (models.storage)
         by calling the method delete
        """
        from models import storage
        storage.delete(self)

    def to_dict(self):
        """Convert instance into dict format"""
        dictionary = {}
        dictionary.update(self.__dict__)
        dictionary.update({"__class__": (str(type(self))
                                         .split(".")[-1]).split("'")[0]})
        dictionary["created_at"] = self.created_at.isoformat()
        dictionary["updated_at"] = self.updated_at.isoformat()
        if "_sa_instance_state" in dictionary.keys():
            del dictionary["_sa_instance_state"]
        if 'password' in dictionary:
            del dictionary['password']
        return dictionary