add orm samples

Author: kohago

hello/try_os.py

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+import os
+
+def test_dir():
+    print("os seprater: " + os.sep)
+
+    #current dir
+    cwd = os.getcwd()
+    print("cwd: "+ cwd)
+
+    #change dir
+    os.chdir("../")
+    cwd = os.getcwd()
+    print("cwd: "+ cwd)
+
+    #parent dir
+    print("parent dir: " + os.path.dirname(cwd))
+    # list dir , list ->str
+    print("list dirs:" + ' '.join(os.listdir(cwd)))
+
+    print(cwd + "is a dir: " + str(os.path.isdir(cwd)))
+    print(" .gitignore is a dir: " + str(os.path.isdir('.gitignore')))
+
+    os.chdir('hello')
+    cwd = os.getcwd()
+    print("-------------")
+    for file in os.listdir(cwd):
+        if file.endswith(".py"):
+            print(file + " is a python file")
+    print("-------------")
+
+test_dir()
+
+

sqlalchemy/README.md

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+sqlite3 samples.db
+sqlite> .schema
+
+sqlite> select * from users

sqlalchemy/database.py

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+# _*_ coding: utf-8 _*_
+import os
+from sqlalchemy import create_engine
+from sqlalchemy.orm import scoped_session,sessionmaker
+from sqlalchemy.ext.declarative import declarative_base
+
+# echo = True,will show generated sql.
+# The echo flag is a shortcut to setting up SQLAlchemy logging, which is accomplished via Python’s standard logging module
+#the SQLite dialect will interpret instructions to the Python built-in sqlite3 module.
+# lazy Connecting, will connect to db will first time it is asked to perform a task
+
+#db engine (sqlite)
+database_file = os.path.join(os.path.abspath(os.path.dirname(__file__)),'samples.db')
+#engine = create_engine('sqlite:///:memory:' echo=True)
+engine = create_engine('sqlite:///' + database_file, echo=True, convert_unicode=True)
+
+#create base class
+#Declarative, which allows us to create classes that include directives to describe the actual database table they will be mapped to.
+Base = declarative_base()
+
+
+#session 
+db_session = scoped_session(sessionmaker(autocommit=False,autoflush=False,bind=engine))
+#query
+Base.query = db_session.query_property()
+
+
+def init_db():
+    #because create a __init__.py in model forlder, we can import it!
+    from model.user import User
+    Base.metadata.create_all(bind=engine)

sqlalchemy/model/__init__.py

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+from sqlalchemy import create_engine,Column,Integer,String
+from database import Base
+
+class User(Base):
+    __tablename__ = 'users'
+
+    id = Column(Integer,primary_key=True)
+    name = Column(String)
+    fullname = Column(String)
+    password = Column(String)
+
+    # __str__ __repr__ is the same
+    # will be called when print(user)
+    def __repr__(self):
+        return "<user(name = '%s',fullname='%s',password='%s')>" % (name,fullname,password)
+
+    def __init__(self,name=None,fullname=None,password=None):
+        self.name = name
+        self.fullname = fullname
+        self.password = password

sqlalchemy/model/user.py

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+from database import init_db,db_session
+from model.user import User
+
+
+#init_db()
+
+user1 = User("hoge1","1Hoge Jim","pw1")
+db_session.add(user1)
+db_session.commit()
+
+user2 = User("hoge2","2Hoge Jim","pw2")
+user3 = User("hoge3","3Hoge Jim","pw3")
+
+db_session.add(user2)
+db_session.add(user3)
+db_session.commit()