model field conversion on assignment

This commit is contained in:
Itai Shirav 2016-06-23 18:24:20 +03:00
parent 25e85adc0d
commit b08f1b3688
6 changed files with 86 additions and 11 deletions

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@ -40,7 +40,7 @@ class Database(object):
self._send(gen())
def count(self, model_class, conditions=None):
query = 'SELECT uniq(height) FROM %s.%s' % (self.db_name, model_class.table_name())
query = 'SELECT count() FROM %s.%s' % (self.db_name, model_class.table_name())
if conditions:
query += ' WHERE ' + conditions
r = self._send(query)

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@ -38,7 +38,7 @@ class StringField(Field):
return value
if isinstance(value, str):
return value.decode('UTF-8')
raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
def get_db_prep_value(self, value):
if isinstance(value, unicode):
@ -58,7 +58,7 @@ class DateField(Field):
return DateField.class_default + datetime.timedelta(days=value)
if isinstance(value, basestring):
return datetime.datetime.strptime(value, '%Y-%m-%d').date()
raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
def get_db_prep_value(self, value):
return value.isoformat()
@ -78,7 +78,7 @@ class DateTimeField(Field):
return datetime.datetime.fromtimestamp(value, pytz.utc)
if isinstance(value, basestring):
return datetime.datetime.strptime(value, '%Y-%m-%d %H-%M-%S')
raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
def get_db_prep_value(self, value):
return int(time.mktime(value.timetuple()))
@ -91,7 +91,7 @@ class BaseIntField(Field):
return value
if isinstance(value, basestring):
return int(value)
raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
class UInt8Field(BaseIntField):
@ -139,9 +139,9 @@ class BaseFloatField(Field):
def to_python(self, value):
if isinstance(value, float):
return value
if isinstance(value, basestring):
if isinstance(value, basestring) or isinstance(value, int):
return float(value)
raise ValueError('Invalid value for %s: %r', self.__class__.__name__, value)
raise ValueError('Invalid value for %s: %r' % (self.__class__.__name__, value))
class Float32Field(BaseFloatField):

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@ -4,10 +4,12 @@ from engines import *
class ModelBase(type):
'''
A metaclass for ORM models. It adds the _fields list to model classes.
'''
def __new__(cls, name, bases, attrs):
new_cls = super(ModelBase, cls).__new__(cls, name, bases, attrs)
#print name, bases, attrs
# Build a list of fields, in the order they were listed in the class
fields = [item for item in attrs.items() if isinstance(item[1], Field)]
fields.sort(key=lambda item: item[1].creation_counter)
@ -16,16 +18,34 @@ class ModelBase(type):
class Model(object):
'''
A base class for ORM models.
'''
__metaclass__ = ModelBase
engine = None
def __init__(self, *args, **kwargs):
def __init__(self, **kwargs):
'''
Creates a model instance, using keyword arguments as field values.
Since values are immediately converted to their Pythonic type,
invalid values will cause a ValueError to be raised.
'''
super(Model, self).__init__()
for name, field in self._fields:
val = kwargs.get(name, field.default)
setattr(self, name, val)
def __setattr__(self, name, value):
field = self.get_field(name)
if field:
value = field.to_python(value)
super(Model, self).__setattr__(name, value)
def get_field(self, name):
field = getattr(self.__class__, name, None)
return field if isinstance(field, Field) else None
@classmethod
def table_name(cls):
return cls.__name__.lower()
@ -54,8 +74,9 @@ class Model(object):
values = iter(parse_tsv(line))
kwargs = {}
for name, field in cls._fields:
kwargs[name] = field.to_python(values.next())
kwargs[name] = values.next()
return cls(**kwargs)
# TODO verify that the number of values matches the number of fields
def to_tsv(self):
'''

0
tests/__init__.py Normal file
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@ -6,7 +6,7 @@ from infi.clickhouse_orm.fields import *
from infi.clickhouse_orm.engines import *
class ORMTestCase(unittest.TestCase):
class DatabaseTestCase(unittest.TestCase):
def setUp(self):
self.database = Database('test_db')

54
tests/test_models.py Normal file
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@ -0,0 +1,54 @@
import unittest
import datetime
import pytz
from infi.clickhouse_orm.models import Model
from infi.clickhouse_orm.fields import *
from infi.clickhouse_orm.engines import *
class ModelTestCase(unittest.TestCase):
def test_defaults(self):
# Check that all fields have their defaults
instance = SimpleModel()
self.assertEquals(instance.date_field, datetime.date(1970, 1, 1))
self.assertEquals(instance.datetime_field, datetime.datetime(1970, 1, 1, tzinfo=pytz.utc))
self.assertEquals(instance.str_field, 'dozo')
self.assertEquals(instance.int_field, 17)
self.assertEquals(instance.float_field, 0)
def test_assignment(self):
# Check that all fields are assigned during construction
kwargs = dict(
date_field=datetime.date(1973, 12, 6),
datetime_field=datetime.datetime(2000, 5, 24, 10, 22, tzinfo=pytz.utc),
str_field='aloha',
int_field=-50,
float_field=3.14
)
instance = SimpleModel(**kwargs)
for name, value in kwargs.items():
self.assertEquals(kwargs[name], getattr(instance, name))
def test_string_conversion(self):
# Check field conversion from string during construction
instance = SimpleModel(date_field='1973-12-06', int_field='100', float_field='7')
self.assertEquals(instance.date_field, datetime.date(1973, 12, 6))
self.assertEquals(instance.int_field, 100)
self.assertEquals(instance.float_field, 7)
# Check field conversion from string during assignment
instance.int_field = '99'
self.assertEquals(instance.int_field, 99)
class SimpleModel(Model):
date_field = DateField()
datetime_field = DateTimeField()
str_field = StringField(default='dozo')
int_field = Int32Field(default=17)
float_field = Float32Field()
engine = MergeTree('date_field', ('int_field', 'date_field'))