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update from atlas

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This commit is contained in:
Luciano Ramalho
2015-03-31 16:53:46 -03:00
parent 290079ec9a
commit 104b2c9d2d
24 changed files with 674 additions and 205 deletions
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16
datamodel/frenchdeck.doctest → 01-data-model/frenchdeck.doctest
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@@ -31,24 +31,24 @@ Card(rank='Q', suit='hearts')
2 Card(rank='3', suit='spades') 2 Card(rank='3', suit='spades')
3 Card(rank='4', suit='spades') 3 Card(rank='4', suit='spades')
... ...
>>> def alt_color_rank(card): >>> suit_values = dict(spades=3, hearts=2, diamonds=1, clubs=0)
>>> def spades_high(card):
... rank_value = FrenchDeck.ranks.index(card.rank) ... rank_value = FrenchDeck.ranks.index(card.rank)
... suits = 'diamonds clubs hearts spades'.split() ... return rank_value * len(suit_values) + suit_values[card.suit]
... return rank_value * len(suits) + suits.index(card.suit)
Rank test: Rank test:
>>> alt_color_rank(Card('2', 'diamonds')) >>> spades_high(Card('2', 'clubs'))
0 0
>>> alt_color_rank(Card('A', 'spades')) >>> spades_high(Card('A', 'spades'))
51 51
>>> for card in sorted(deck, key=alt_color_rank): # doctest: +ELLIPSIS >>> for card in sorted(deck, key=spades_high): # doctest: +ELLIPSIS
... print(card) ... print(card)
Card(rank='2', suit='diamonds')
Card(rank='2', suit='clubs') Card(rank='2', suit='clubs')
Card(rank='2', suit='diamonds')
Card(rank='2', suit='hearts') Card(rank='2', suit='hearts')
... ...
Card(rank='A', suit='clubs') Card(rank='A', suit='diamonds')
Card(rank='A', suit='hearts') Card(rank='A', suit='hearts')
Card(rank='A', suit='spades') Card(rank='A', suit='spades')

0
datamodel/frenchdeck.py → 01-data-model/frenchdeck.py
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0
datamodel/vector2d.py → 01-data-model/vector2d.py
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18
02-array-seq/listcomp_speed.py Normal file
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@@ -0,0 +1,18 @@
import timeit
TIMES = 10000
SETUP = """
symbols = '$¢£¥€¤'
def non_ascii(c):
return c > 127
"""
def clock(label, cmd):
res = timeit.repeat(cmd, setup=SETUP, number=TIMES)
print(label, *('{:.3f}'.format(x) for x in res))
clock('listcomp :', '[ord(s) for s in symbols if ord(s) > 127]')
clock('listcomp + func :', '[ord(s) for s in symbols if non_ascii(ord(s))]')
clock('filter + lambda :', 'list(filter(lambda c: c > 127, map(ord, symbols)))')
clock('filter + func :', 'list(filter(non_ascii, map(ord, symbols)))')

22
21-class-metaprog/evaldecos.py
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@@ -1,22 +0,0 @@
def deco_alpha(func):
print('<<100>> deco_alpha')
def inner_alpha():
print('<<200>> deco_alpha')
func()
return inner_alpha
def deco_beta(cls):
print('<<300>> deco_beta')
def inner_beta(self):
print('<<400>> inner_beta')
print("result from 'deco_beta::inner_beta'")
cls.method3 = inner_beta
return cls
print('<<500>> evaldecos mudule body')

25
21-class-metaprog/evalsupport.py Normal file
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@@ -0,0 +1,25 @@
print('<[100]> evalsupport module start')
def deco_alpha(cls):
print('<[200]> deco_alpha')
def inner_1(self):
print('<[300]> deco_alpha:inner_1')
cls.method_y = inner_1
return cls
# BEGIN META_ALEPH
class MetaAleph(type):
print('<[400]> MetaAleph body')
def __init__(self, name, bases, dic):
print('<[500]> MetaAleph.__init__')
def inner_2(self):
print('<[600]> MetaAleph.__init__:inner_2')
self.method_z = inner_2
# END META_ALEPH
print('<[700]> evalsupport module end')

101
21-class-metaprog/evaltime.py
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@@ -1,92 +1,49 @@
import atexit from evalsupport import deco_alpha
from evaldecos import deco_alpha print('<[1]> evaltime module start')
from evaldecos import deco_beta
print('<<1>> start') class ClassOne():
print('<[2]> ClassOne body')
def __init__(self):
print('<[3]> ClassOne.__init__')
func_A = lambda: print('<<2>> func_A') def __del__(self):
print('<[4]> ClassOne.__del__')
def method_x(self):
print('<[5]> ClassOne.method_x')
def func_B(): class ClassTwo(object):
print('<<3>> func_B') print('<[6]> ClassTwo body')
def func_C():
print('<<4>> func_C')
return func_C
@deco_alpha @deco_alpha
def func_D(): class ClassThree():
print('<<6>> func_D') print('<[7]> ClassThree body')
def method_y(self):
print('<[8]> ClassThree.method_y')
def func_E(): class ClassFour(ClassThree):
print('<<7>> func_E') print('<[9]> ClassFour body')
def method_y(self):
class ClassOne(object): print('<[10]> ClassFour.method_y')
print('<<7>> ClassOne body')
def __init__(self):
print('<<8>> ClassOne.__init__')
def __del__(self):
print('<<9>> ClassOne.__del__')
def method1(self):
print('<<10>> ClassOne.method')
return "result from 'ClassOne.method1'"
class ClassTwo(object):
print('<<11>> ClassTwo body')
@deco_beta
class ClassThree(ClassOne):
print('<<12>> ClassThree body')
def method3(self):
print('<<13>> ClassOne.method')
return "result from 'ClassThree.method3'"
if True:
print("<<14>> 'if True'")
if False:
print("<<15>> 'if False'")
atexit.register(func_E)
print("<<16>> right before 'if ... __main__'")
if __name__ == '__main__': if __name__ == '__main__':
print('<<17>> start __main__ block') print('<[11]> ClassOne tests', 30 * '.')
print(func_A)
print(func_A())
print('<<18>> continue __main__ block')
print(func_B)
b_result = func_B()
print(b_result)
one = ClassOne() one = ClassOne()
one.method1() one.method_x()
b_result() print('<[12]> ClassThree tests', 30 * '.')
print(func_D)
func_D()
three = ClassThree() three = ClassThree()
three.method3() three.method_y()
print('<[13]> ClassFour tests', 30 * '.')
class ClassFour(object): four = ClassFour()
print('<<19>> ClasFour body') four.method_y()
print('<<20>> end __main__ block')
print('<<21>> The End') print('<[14]> evaltime module end')

53
21-class-metaprog/evaltime_meta.py Normal file
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@@ -0,0 +1,53 @@
from evalsupport import deco_alpha
from evalsupport import MetaAleph
print('<[1]> evaltime_meta module start')
@deco_alpha
class ClassThree():
print('<[2]> ClassThree body')
def method_y(self):
print('<[3]> ClassThree.method_y')
class ClassFour(ClassThree):
print('<[4]> ClassFour body')
def method_y(self):
print('<[5]> ClassFour.method_y')
class ClassFive(metaclass=MetaAleph):
print('<[6]> ClassFive body')
def __init__(self):
print('<[7]> ClassFive.__init__')
def method_z(self):
print('<[8]> ClassFive.method_y')
class ClassSix(ClassFive):
print('<[9]> ClassSix body')
def method_z(self):
print('<[10]> ClassSix.method_y')
if __name__ == '__main__':
print('<[11]> ClassThree tests', 30 * '.')
three = ClassThree()
three.method_y()
print('<[12]> ClassFour tests', 30 * '.')
four = ClassFour()
four.method_y()
print('<[13]> ClassFive tests', 30 * '.')
five = ClassFive()
five.method_z()
print('<[14]> ClassSix tests', 30 * '.')
six = ClassSix()
six.method_z()
print('<[15]> evaltime_meta module end')

20
21-class-metaprog/factories.py
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@@ -9,12 +9,12 @@ record_factory: create simple classes just for holding data fields
>>> name, weight, _ = rex # <3> >>> name, weight, _ = rex # <3>
>>> name, weight >>> name, weight
('Rex', 30) ('Rex', 30)
>>> "{2}'s dog weights {1}kg".format(*rex) >>> "{2}'s dog weights {1}kg".format(*rex) # <4>
"Bob's dog weights 30kg" "Bob's dog weights 30kg"
>>> rex.weight = 32 # <4> >>> rex.weight = 32 # <5>
>>> rex >>> rex
Dog(name='Rex', weight=32, owner='Bob') Dog(name='Rex', weight=32, owner='Bob')
>>> Dog.__mro__ # <5> >>> Dog.__mro__ # <6>
(<class 'factories.Dog'>, <class 'object'>) (<class 'factories.Dog'>, <class 'object'>)
# END RECORD_FACTORY_DEMO # END RECORD_FACTORY_DEMO
@@ -22,29 +22,29 @@ record_factory: create simple classes just for holding data fields
# BEGIN RECORD_FACTORY # BEGIN RECORD_FACTORY
def record_factory(cls_name, field_names): def record_factory(cls_name, field_names):
if isinstance(field_names, str): # <1> if isinstance(field_names, str):
field_names = field_names.replace(',', ' ').split() field_names = field_names.replace(',', ' ').split()
__slots__ = tuple(field_names) field_names = tuple(field_names) # <1>
def __init__(self, *args, **kwargs): def __init__(self, *args, **kwargs): # <2>
attrs = dict(zip(self.__slots__, args)) attrs = dict(zip(self.__slots__, args))
attrs.update(kwargs) attrs.update(kwargs)
for name, value in attrs.items(): for name, value in attrs.items():
setattr(self, name, value) setattr(self, name, value)
def __iter__(self): def __iter__(self): # <3>
for name in self.__slots__: for name in self.__slots__:
yield getattr(self, name) yield getattr(self, name)
def __repr__(self): def __repr__(self): # <4>
values = ', '.join('{}={!r}'.format(*i) for i values = ', '.join('{}={!r}'.format(*i) for i
in zip(self.__slots__, self)) in zip(self.__slots__, self))
return '{}({})'.format(self.__class__.__name__, values) return '{}({})'.format(self.__class__.__name__, values)
cls_attrs = dict(__slots__ = __slots__, cls_attrs = dict(__slots__ = field_names, # <5>
__init__ = __init__, __init__ = __init__,
__iter__ = __iter__, __iter__ = __iter__,
__repr__ = __repr__) __repr__ = __repr__)
return type(cls_name, (object,), cls_attrs) return type(cls_name, (object,), cls_attrs) # <6>
# END RECORD_FACTORY # END RECORD_FACTORY

4
datamodel/tox.ini
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@@ -1,4 +0,0 @@
[pep8]
ignore = E127,E302
# E127: continuation line over-indented for visual indent
# E302: expected 2 blank lines, found 1

8
descriptors/bulkfood_v4.py
View File

@@ -29,11 +29,11 @@ instance::
>>> raisins = LineItem('Golden raisins', 10, 6.95) >>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE >>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
['_Quantity:0', '_Quantity:1', '__class__', ... ['_Quantity#0', '_Quantity#1', '__class__', ...
'description', 'price', 'subtotal', 'weight'] 'description', 'price', 'subtotal', 'weight']
>>> getattr(raisins, '_Quantity:0') >>> getattr(raisins, '_Quantity#0')
10 10
>>> getattr(raisins, '_Quantity:1') >>> getattr(raisins, '_Quantity#1')
6.95 6.95
""" """
@@ -47,7 +47,7 @@ class Quantity:
cls = self.__class__ # <2> cls = self.__class__ # <2>
prefix = cls.__name__ prefix = cls.__name__
index = cls.__counter index = cls.__counter
self.storage_name = '_{}:{}'.format(prefix, index) # <3> self.storage_name = '_{}#{}'.format(prefix, index) # <3>
cls.__counter += 1 # <4> cls.__counter += 1 # <4>
def __get__(self, instance, owner): # <5> def __get__(self, instance, owner): # <5>

15
descriptors/bulkfood_v4b.py
View File

@@ -29,21 +29,20 @@ instance::
>>> raisins = LineItem('Golden raisins', 10, 6.95) >>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE >>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
['_Quantity:0', '_Quantity:1', '__class__', ... ['_Quantity#0', '_Quantity#1', '__class__', ...
'description', 'price', 'subtotal', 'weight'] 'description', 'price', 'subtotal', 'weight']
>>> getattr(raisins, '_Quantity:0') >>> getattr(raisins, '_Quantity#0')
10 10
>>> getattr(raisins, '_Quantity:1') >>> getattr(raisins, '_Quantity#1')
6.95 6.95
If the descriptor is accessed in the class, the descriptor object is If the descriptor is accessed in the class, the descriptor object is
returned: returned:
>>> LineItem.price # doctest: +ELLIPSIS >>> LineItem.weight # doctest: +ELLIPSIS
<bulkfood_v4b.Quantity object at 0x...> <bulkfood_v4b.Quantity object at 0x...>
>>> br_nuts = LineItem('Brazil nuts', 10, 34.95) >>> LineItem.weight.storage_name
>>> br_nuts.price '_Quantity#0'
34.95
""" """
@@ -56,7 +55,7 @@ class Quantity:
cls = self.__class__ cls = self.__class__
prefix = cls.__name__ prefix = cls.__name__
index = cls.__counter index = cls.__counter
self.storage_name = '_{}:{}'.format(prefix, index) self.storage_name = '_{}#{}'.format(prefix, index)
cls.__counter += 1 cls.__counter += 1
def __get__(self, instance, owner): def __get__(self, instance, owner):

14
descriptors/bulkfood_v4c.py
View File

@@ -29,21 +29,21 @@ instance::
>>> raisins = LineItem('Golden raisins', 10, 6.95) >>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE >>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
['_Quantity:0', '_Quantity:1', '__class__', ... ['_Quantity#0', '_Quantity#1', '__class__', ...
'description', 'price', 'subtotal', 'weight'] 'description', 'price', 'subtotal', 'weight']
>>> getattr(raisins, '_Quantity:0') >>> getattr(raisins, '_Quantity#0')
10 10
>>> getattr(raisins, '_Quantity:1') >>> getattr(raisins, '_Quantity#1')
6.95 6.95
If the descriptor is accessed in the class, the descriptor object is If the descriptor is accessed in the class, the descriptor object is
returned: returned:
>>> LineItem.price # doctest: +ELLIPSIS >>> LineItem.weight # doctest: +ELLIPSIS
<model_v4c.Quantity object at 0x...> <model_v4c.Quantity object at 0x...>
>>> br_nuts = LineItem('Brazil nuts', 10, 34.95) >>> LineItem.weight.storage_name
>>> br_nuts.price '_Quantity#0'
34.95
""" """

18
descriptors/bulkfood_v5.py
View File

@@ -29,29 +29,33 @@ instance::
>>> raisins = LineItem('Golden raisins', 10, 6.95) >>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE >>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
['_NonBlank:0', '_Quantity:0', '_Quantity:1', '__class__', ... ['_NonBlank#0', '_Quantity#0', '_Quantity#1', '__class__', ...
'description', 'price', 'subtotal', 'weight'] 'description', 'price', 'subtotal', 'weight']
>>> getattr(raisins, '_Quantity:0') >>> getattr(raisins, '_Quantity#0')
10 10
>>> getattr(raisins, '_NonBlank:0') >>> getattr(raisins, '_NonBlank#0')
'Golden raisins' 'Golden raisins'
If the descriptor is accessed in the class, the descriptor object is If the descriptor is accessed in the class, the descriptor object is
returned: returned:
>>> LineItem.price # doctest: +ELLIPSIS >>> LineItem.weight # doctest: +ELLIPSIS
<model_v5.Quantity object at 0x...> <model_v5.Quantity object at 0x...>
>>> br_nuts = LineItem('Brazil nuts', 10, 34.95) >>> LineItem.weight.storage_name
>>> br_nuts.price '_Quantity#0'
34.95
The `NonBlank` descriptor prevents empty or blank strings to be used The `NonBlank` descriptor prevents empty or blank strings to be used
for the description: for the description:
>>> br_nuts = LineItem('Brazil Nuts', 10, 34.95)
>>> br_nuts.description = ' ' >>> br_nuts.description = ' '
Traceback (most recent call last): Traceback (most recent call last):
... ...
ValueError: value cannot be empty or blank ValueError: value cannot be empty or blank
>>> void = LineItem('', 1, 1)
Traceback (most recent call last):
...
ValueError: value cannot be empty or blank
""" """

85
descriptors/bulkfood_v5_check.py Normal file
View File

@@ -0,0 +1,85 @@
"""
A line item for a bulk food order has description, weight and price fields::
>>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> raisins.weight, raisins.description, raisins.price
(10, 'Golden raisins', 6.95)
A ``subtotal`` method gives the total price for that line item::
>>> raisins.subtotal()
69.5
The weight of a ``LineItem`` must be greater than 0::
>>> raisins.weight = -20
Traceback (most recent call last):
...
ValueError: value must be > 0; -20 is not valid.
No change was made::
>>> raisins.weight
10
The value of the attributes managed by the descriptors are stored in
alternate attributes, created by the descriptors in each ``LineItem``
instance::
>>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
['_Check#0', '_Check#1', '_Check#2', '__class__', ...
'description', 'price', 'subtotal', 'weight']
>>> [getattr(raisins, name) for name in dir(raisins) if name.startswith('_Check#')]
['Golden raisins', 10, 6.95]
If the descriptor is accessed in the class, the descriptor object is
returned:
>>> LineItem.weight # doctest: +ELLIPSIS
<model_v5_check.Check object at 0x...>
>>> LineItem.weight.storage_name
'_Check#1'
The `NonBlank` descriptor prevents empty or blank strings to be used
for the description:
>>> br_nuts = LineItem('Brazil Nuts', 10, 34.95)
>>> br_nuts.description = ' '
Traceback (most recent call last):
...
ValueError: ' ' is not valid.
>>> void = LineItem('', 1, 1)
Traceback (most recent call last):
...
ValueError: '' is not valid.
"""
import model_v5_check as model
def gt_zero(x):
'''value must be > 0'''
return x if x > 0 else model.INVALID
def non_blank(txt):
txt = txt.strip()
return txt if txt else model.INVALID
class LineItem:
description = model.Check(non_blank)
weight = model.Check(gt_zero)
price = model.Check(gt_zero)
def __init__(self, description, weight, price):
self.description = description
self.weight = weight
self.price = price
def subtotal(self):
return self.weight * self.price

57
descriptors/bulkfood_v6.py
View File

@@ -16,7 +16,7 @@ The weight of a ``LineItem`` must be greater than 0::
>>> raisins.weight = -20 >>> raisins.weight = -20
Traceback (most recent call last): Traceback (most recent call last):
... ...
ValueError: value must be > 0; -20 is not valid. ValueError: value must be > 0
No change was made:: No change was made::
@@ -27,49 +27,52 @@ The value of the attributes managed by the descriptors are stored in
alternate attributes, created by the descriptors in each ``LineItem`` alternate attributes, created by the descriptors in each ``LineItem``
instance:: instance::
# BEGIN LINEITEM_V6_DEMO
>>> raisins = LineItem('Golden raisins', 10, 6.95) >>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> dir(raisins) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE >>> dir(raisins)[:3]
['_Check:0', '_Check:1', '_Check:2', '__class__', ... ['_NonBlank#description', '_Quantity#price', '_Quantity#weight']
'description', 'price', 'subtotal', 'weight'] >>> LineItem.description.storage_name
>>> [getattr(raisins, name) for name in dir(raisins) if name.startswith('_Check:')] '_NonBlank#description'
['Golden raisins', 10, 6.95] >>> raisins.description
'Golden raisins'
>>> getattr(raisins, '_NonBlank#description')
'Golden raisins'
# END LINEITEM_V6_DEMO
If the descriptor is accessed in the class, the descriptor object is If the descriptor is accessed in the class, the descriptor object is
returned: returned:
>>> LineItem.price # doctest: +ELLIPSIS >>> LineItem.weight # doctest: +ELLIPSIS
<model_v6.Check object at 0x...> <model_v6.Quantity object at 0x...>
>>> br_nuts = LineItem('Brazil nuts', 10, 34.95) >>> LineItem.weight.storage_name
>>> br_nuts.price '_Quantity#weight'
34.95
The `NonBlank` descriptor prevents empty or blank strings to be used The `NonBlank` descriptor prevents empty or blank strings to be used
for the description: for the description:
>>> br_nuts = LineItem('Brazil Nuts', 10, 34.95)
>>> br_nuts.description = ' ' >>> br_nuts.description = ' '
Traceback (most recent call last): Traceback (most recent call last):
... ...
ValueError: ' ' is not valid. ValueError: value cannot be empty or blank
>>> void = LineItem('', 1, 1)
Traceback (most recent call last):
...
ValueError: value cannot be empty or blank
""" """
# BEGIN LINEITEM_V5 # BEGIN LINEITEM_V6
import model_v6 as model # <1> import model_v6 as model
def gt_zero(x):
'''value must be > 0'''
return x if x > 0 else model.INVALID
def non_blank(txt):
txt = txt.strip()
return txt if txt else model.INVALID
@model.entity # <1>
class LineItem: class LineItem:
description = model.Check(non_blank) # <2> description = model.NonBlank()
weight = model.Check(gt_zero) weight = model.Quantity()
price = model.Check(gt_zero) price = model.Quantity()
def __init__(self, description, weight, price): def __init__(self, description, weight, price):
self.description = description self.description = description
@@ -78,4 +81,4 @@ class LineItem:
def subtotal(self): def subtotal(self):
return self.weight * self.price return self.weight * self.price
# END LINEITEM_V5 # END LINEITEM_V6

79
descriptors/bulkfood_v7.py Normal file
View File

@@ -0,0 +1,79 @@
"""
A line item for a bulk food order has description, weight and price fields::
>>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> raisins.weight, raisins.description, raisins.price
(10, 'Golden raisins', 6.95)
A ``subtotal`` method gives the total price for that line item::
>>> raisins.subtotal()
69.5
The weight of a ``LineItem`` must be greater than 0::
>>> raisins.weight = -20
Traceback (most recent call last):
...
ValueError: value must be > 0
No change was made::
>>> raisins.weight
10
The value of the attributes managed by the descriptors are stored in
alternate attributes, created by the descriptors in each ``LineItem``
instance::
>>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> dir(raisins)[:3]
['_NonBlank#description', '_Quantity#price', '_Quantity#weight']
>>> LineItem.description.storage_name
'_NonBlank#description'
>>> raisins.description
'Golden raisins'
>>> getattr(raisins, '_NonBlank#description')
'Golden raisins'
If the descriptor is accessed in the class, the descriptor object is
returned:
>>> LineItem.weight # doctest: +ELLIPSIS
<model_v7.Quantity object at 0x...>
>>> LineItem.weight.storage_name
'_Quantity#weight'
The `NonBlank` descriptor prevents empty or blank strings to be used
for the description:
>>> br_nuts = LineItem('Brazil Nuts', 10, 34.95)
>>> br_nuts.description = ' '
Traceback (most recent call last):
...
ValueError: value cannot be empty or blank
>>> void = LineItem('', 1, 1)
Traceback (most recent call last):
...
ValueError: value cannot be empty or blank
"""
# BEGIN LINEITEM_V7
import model_v7 as model
class LineItem(model.Entity): # <1>
description = model.NonBlank()
weight = model.Quantity()
price = model.Quantity()
def __init__(self, description, weight, price):
self.description = description
self.weight = weight
self.price = price
def subtotal(self):
return self.weight * self.price
# END LINEITEM_V7

86
descriptors/bulkfood_v8.py Normal file
View File

@@ -0,0 +1,86 @@
"""
A line item for a bulk food order has description, weight and price fields::
>>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> raisins.weight, raisins.description, raisins.price
(10, 'Golden raisins', 6.95)
A ``subtotal`` method gives the total price for that line item::
>>> raisins.subtotal()
69.5
The weight of a ``LineItem`` must be greater than 0::
>>> raisins.weight = -20
Traceback (most recent call last):
...
ValueError: value must be > 0
No change was made::
>>> raisins.weight
10
>>> raisins = LineItem('Golden raisins', 10, 6.95)
>>> dir(raisins)[:3]
['_NonBlank#description', '_Quantity#price', '_Quantity#weight']
>>> LineItem.description.storage_name
'_NonBlank#description'
>>> raisins.description
'Golden raisins'
>>> getattr(raisins, '_NonBlank#description')
'Golden raisins'
If the descriptor is accessed in the class, the descriptor object is
returned:
>>> LineItem.weight # doctest: +ELLIPSIS
<model_v8.Quantity object at 0x...>
>>> LineItem.weight.storage_name
'_Quantity#weight'
The `NonBlank` descriptor prevents empty or blank strings to be used
for the description:
>>> br_nuts = LineItem('Brazil Nuts', 10, 34.95)
>>> br_nuts.description = ' '
Traceback (most recent call last):
...
ValueError: value cannot be empty or blank
>>> void = LineItem('', 1, 1)
Traceback (most recent call last):
...
ValueError: value cannot be empty or blank
Fields can be retrieved in the order they were declared:
# BEGIN LINEITEM_V8_DEMO
>>> for name in LineItem.field_names():
... print(name)
...
description
weight
price
# END LINEITEM_V8_DEMO
"""
import model_v8 as model
class LineItem(model.Entity):
description = model.NonBlank()
weight = model.Quantity()
price = model.Quantity()
def __init__(self, description, weight, price):
self.description = description
self.weight = weight
self.price = price
def subtotal(self):
return self.weight * self.price

2
descriptors/model_v4c.py
View File

@@ -6,7 +6,7 @@ class Quantity:
cls = self.__class__ cls = self.__class__
prefix = cls.__name__ prefix = cls.__name__
index = cls.__counter index = cls.__counter
self.storage_name = '_{}:{}'.format(prefix, index) self.storage_name = '_{}#{}'.format(prefix, index)
cls.__counter += 1 cls.__counter += 1
def __get__(self, instance, owner): def __get__(self, instance, owner):

2
descriptors/model_v5.py
View File

@@ -9,7 +9,7 @@ class AutoStorage: # <1>
cls = self.__class__ cls = self.__class__
prefix = cls.__name__ prefix = cls.__name__
index = cls.__counter index = cls.__counter
self.storage_name = '_{}:{}'.format(prefix, index) self.storage_name = '_{}#{}'.format(prefix, index)
cls.__counter += 1 cls.__counter += 1
def __get__(self, instance, owner): def __get__(self, instance, owner):

52
descriptors/model_v5_check.py Normal file
View File

@@ -0,0 +1,52 @@
import abc
class AutoStorage:
__counter = 0
def __init__(self):
cls = self.__class__
prefix = cls.__name__
index = cls.__counter
self.storage_name = '_{}#{}'.format(prefix, index)
cls.__counter += 1
def __get__(self, instance, owner):
if instance is None:
return self
else:
return getattr(instance, self.storage_name)
def __set__(self, instance, value):
setattr(instance, self.storage_name, value)
class Validated(abc.ABC, AutoStorage):
def __set__(self, instance, value):
value = self.validate(instance, value)
super().__set__(instance, value)
@abc.abstractmethod
def validate(self, instance, value):
"""return validated value or raise ValueError"""
INVALID = object()
class Check(Validated):
def __init__(self, checker):
super().__init__()
self.checker = checker
if checker.__doc__ is None:
doc = ''
else:
doc = checker.__doc__ + '; '
self.message = doc + '{!r} is not valid.'
def validate(self, instance, value):
result = self.checker(value)
if result is INVALID:
raise ValueError(self.message.format(value))
return result

50
descriptors/model_v6.py
View File

@@ -1,15 +1,14 @@
# BEGIN MODEL_V5
import abc import abc
class AutoStorage: # <1> class AutoStorage:
__counter = 0 __counter = 0
def __init__(self): def __init__(self):
cls = self.__class__ cls = self.__class__
prefix = cls.__name__ prefix = cls.__name__
index = cls.__counter index = cls.__counter
self.storage_name = '_{}:{}'.format(prefix, index) self.storage_name = '_{}#{}'.format(prefix, index)
cls.__counter += 1 cls.__counter += 1
def __get__(self, instance, owner): def __get__(self, instance, owner):
@@ -19,41 +18,22 @@ class AutoStorage: # <1>
return getattr(instance, self.storage_name) return getattr(instance, self.storage_name)
def __set__(self, instance, value): def __set__(self, instance, value):
setattr(instance, self.storage_name, value) # <2> setattr(instance, self.storage_name, value)
class Validated(abc.ABC, AutoStorage): # <3> class Validated(abc.ABC, AutoStorage):
def __set__(self, instance, value): def __set__(self, instance, value):
value = self.validate(instance, value) # <4> value = self.validate(instance, value)
super().__set__(instance, value) # <5> super().__set__(instance, value)
@abc.abstractmethod @abc.abstractmethod
def validate(self, instance, value): # <6> def validate(self, instance, value):
"""return validated value or raise ValueError""" """return validated value or raise ValueError"""
INVALID = object()
class Check(Validated): class Quantity(Validated):
"""a number greater than zero"""
def __init__(self, checker):
super().__init__()
self.checker = checker
if checker.__doc__ is None:
doc = ''
else:
doc = checker.__doc__ + '; '
self.message = doc + '{!r} is not valid.'
def validate(self, instance, value):
result = self.checker(value)
if result is INVALID:
raise ValueError(self.message.format(value))
return result
class Quantity(Validated): # <7>
def validate(self, instance, value): def validate(self, instance, value):
if value <= 0: if value <= 0:
@@ -62,11 +42,19 @@ class Quantity(Validated): # <7>
class NonBlank(Validated): class NonBlank(Validated):
"""a string with at least one non-space character"""
def validate(self, instance, value): def validate(self, instance, value):
value = value.strip() value = value.strip()
if len(value) == 0: if len(value) == 0:
raise ValueError('value cannot be empty or blank') raise ValueError('value cannot be empty or blank')
return value # <8> return value
# END MODEL_V5 # BEGIN MODEL_V6
def entity(cls): # <1>
for key, attr in cls.__dict__.items(): # <2>
if isinstance(attr, Validated): # <3>
type_name = type(attr).__name__
attr.storage_name = '_{}#{}'.format(type_name, key) # <4>
return cls # <5>
# END MODEL_V6

66
descriptors/model_v7.py Normal file
View File

@@ -0,0 +1,66 @@
import abc
class AutoStorage:
__counter = 0
def __init__(self):
cls = self.__class__
prefix = cls.__name__
index = cls.__counter
self.storage_name = '_{}#{}'.format(prefix, index)
cls.__counter += 1
def __get__(self, instance, owner):
if instance is None:
return self
else:
return getattr(instance, self.storage_name)
def __set__(self, instance, value):
setattr(instance, self.storage_name, value)
class Validated(abc.ABC, AutoStorage):
def __set__(self, instance, value):
value = self.validate(instance, value)
super().__set__(instance, value)
@abc.abstractmethod
def validate(self, instance, value):
"""return validated value or raise ValueError"""
class Quantity(Validated):
"""a number greater than zero"""
def validate(self, instance, value):
if value <= 0:
raise ValueError('value must be > 0')
return value
class NonBlank(Validated):
"""a string with at least one non-space character"""
def validate(self, instance, value):
value = value.strip()
if len(value) == 0:
raise ValueError('value cannot be empty or blank')
return value
# BEGIN MODEL_V7
class EntityMeta(type):
"""Metaclass for business entities with validated fields"""
def __init__(self, name, bases, attr_dict):
super().__init__(name, bases, attr_dict) # <1>
for key, attr in attr_dict.items(): # <2>
if isinstance(attr, Validated):
type_name = type(attr).__name__
attr.storage_name = '_{}#{}'.format(type_name, key)
class Entity(metaclass=EntityMeta): # <3>
"""Business entity with validated fields"""
# END MODEL_V7

80
descriptors/model_v8.py Normal file
View File

@@ -0,0 +1,80 @@
import abc
import collections
class AutoStorage:
__counter = 0
def __init__(self):
cls = self.__class__
prefix = cls.__name__
index = cls.__counter
self.storage_name = '_{}#{}'.format(prefix, index)
cls.__counter += 1
def __get__(self, instance, owner):
if instance is None:
return self
else:
return getattr(instance, self.storage_name)
def __set__(self, instance, value):
setattr(instance, self.storage_name, value)
class Validated(abc.ABC, AutoStorage):
def __set__(self, instance, value):
value = self.validate(instance, value)
super().__set__(instance, value)
@abc.abstractmethod
def validate(self, instance, value):
"""return validated value or raise ValueError"""
class Quantity(Validated):
"""a number greater than zero"""
def validate(self, instance, value):
if value <= 0:
raise ValueError('value must be > 0')
return value
class NonBlank(Validated):
"""a string with at least one non-space character"""
def validate(self, instance, value):
value = value.strip()
if len(value) == 0:
raise ValueError('value cannot be empty or blank')
return value
# BEGIN MODEL_V8
class EntityMeta(type):
"""Metaclass for business entities with validated fields"""
@classmethod
def __prepare__(cls, name, bases):
return collections.OrderedDict() # <1>
def __init__(self, name, bases, attr_dict):
super().__init__(name, bases, attr_dict)
self._field_names = [] # <2>
for key, attr in attr_dict.items(): # <3>
if isinstance(attr, Validated):
type_name = type(attr).__name__
attr.storage_name = '_{}#{}'.format(type_name, key)
self._field_names.append(key) # <4>
class Entity(metaclass=EntityMeta):
"""Business entity with validated fields"""
@classmethod
def field_names(cls): # <5>
for name in cls._field_names:
yield name
# END MODEL_V8