pythonsqlalchemy

How to convert SQLAlchemy row object to a Python dict?


Is there a simple way to iterate over column name and value pairs?

My version of SQLAlchemy is 0.5.6

Here is the sample code where I tried using dict(row):

import sqlalchemy
from sqlalchemy import *
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

print "sqlalchemy version:",sqlalchemy.__version__ 

engine = create_engine('sqlite:///:memory:', echo=False)
metadata = MetaData()
users_table = Table('users', metadata,
     Column('id', Integer, primary_key=True),
     Column('name', String),
)
metadata.create_all(engine) 

class User(declarative_base()):
    __tablename__ = 'users'
    
    id = Column(Integer, primary_key=True)
    name = Column(String)
    
    def __init__(self, name):
        self.name = name

Session = sessionmaker(bind=engine)
session = Session()

user1 = User("anurag")
session.add(user1)
session.commit()

# uncommenting next line throws exception 'TypeError: 'User' object is not iterable'
#print dict(user1)
# this one also throws 'TypeError: 'User' object is not iterable'
for u in session.query(User).all():
    print dict(u)

Running this code on my system outputs:

Traceback (most recent call last):
  File "untitled-1.py", line 37, in <module>
    print dict(u)
TypeError: 'User' object is not iterable

Solution

  • I couldn't get a good answer so I use this:

    def row2dict(row):
        d = {}
        for column in row.__table__.columns:
            d[column.name] = str(getattr(row, column.name))
    
        return d
    

    Edit: if above function is too long and not suited for some tastes here is a one liner (python 2.7+)

    row2dict = lambda r: {c.name: str(getattr(r, c.name)) for c in r.__table__.columns}