1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
# -*- coding: utf-8 -*-
class Field(object):
def __init__(self, name, column_type, required, field_type):
self.name = name
self.column_type = column_type
self.required = required
self.field_type = field_type
def __str__(self):
return '<%s:%s>' % (self.__class__.__name__, self.name)
class StringField(Field):
def __init__(self, name, required=False, field_type=str):
super(StringField, self).__init__(name, 'varchar(100)', required,
field_type)
class IntegerField(Field):
def __init__(self, name, required=False, field_type=int):
super(IntegerField, self).__init__(name, 'int', required, field_type)
class ModelMetaclass(type):
def __new__(cls, name, bases, attrs):
if name=='Model':
return type.__new__(cls, name, bases, attrs)
mappings = dict()
requireds = dict()
field_type = dict()
for k, v in attrs.items():
if isinstance(v, Field):
mappings[k] = v
field_type[k] = v.field_type
if v.required:
requireds[k] = 'required'
for k in mappings.keys():
attrs.pop(k)
attrs['__mappings__'] = mappings
attrs['__table__'] = name
attrs['__requireds__'] = requireds
attrs['__field_type__'] = field_type
return type.__new__(cls, name, bases, attrs)
class Model(dict, metaclass=ModelMetaclass):
def __init__(self, **kw):
self.fields = kw
if self.check_fields():
super(Model, self).__init__(**kw)
def __getattr__(self, key):
try:
return self[key]
except KeyError:
raise AttributeError(r"'Model' object has no attribute '%s'" % key)
def __setattr__(self, key, value):
self[key] = value
def check_fields(self):
kw = self.fields
required_fields = set(type(self).__dict__['__requireds__'])
applied_fields = set(kw)
missed_fields = required_fields - applied_fields
field_type = type(self).__dict__['__field_type__']
if len(missed_fields) == 0:
for k, v in kw.items():
if isinstance(kw[k], field_type[k]):
continue
else:
raise TypeError('Field type error')
return True
else:
raise ValueError('Field %s required' % missed_fields)
def save(self):
fields = []
params = []
args = []
for k, v in self.__mappings__.items():
fields.append(v.name)
params.append('?')
args.append(getattr(self, k, None))
sql = 'insert into %s (%s) values (%s)' % (self.__table__,
', '.join(fields), ', '.join(str(arg) for arg in args))
print('SQL: %s' % sql)
print('ARGS: %s' % str(args))
class User(Model):
uid = IntegerField('id')
name = StringField('username', required=True)
email = StringField('email')
password = StringField('password', required=True)
if __name__ == '__main__':
u = User(uid=10001, name='Joe', email='[email protected]', password='10001')
u.save()
|
近期评论