Using Databases With Python
Databases#
ORM - Object Relational Mapper#
Convert rows in tables into object (Models) in code
A simple lightweight one is called peewee
How to import everything
from peewee import *
Working with Mysql#
sudo pip install pymysql
then:
db = MySQLDatabase('peewee')
from peewee import *
make connection to db#
db = MySQLDatabase('peewee', user='root', password='pass')
# classes inherit from model
# always name models for singular name
# represents a single item in db
class Student(Model):
username = CharField(max_length=255, unique=True)
points = IntegerField(default=0)
# tell model what database it belongs to
# class inside of classs
class Meta:
database = db
students = [
{'username': 'stephen', 'points':45},
{'username': 'squash', 'points':100},
{'username': 'pat', 'points':150},
{'username': 'matt', 'points':30},
{'username': 'casey', 'points':1345}
]
def add_students():
for student in students:
Student.create(username=Student.username, points=Student.points)
# if run directly and not imported
if __name__ == '__main__':
db.connect()
db.create_tables([Student], safe=True)
add_students()
Making queries#
create()select()save()get()delete_instance()
Switches#
Python intentionally does not have switches
Can use a dictionary but has no order
So can use an ordered dict
from collections import OrderedDict
Items must be added like a list