daviddoji/example-code-2e
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

removed 1st edition code

Browse Source
This commit is contained in:
Luciano Ramalho
2020-03-11 18:03:55 -03:00
parent 1be97eea3e
commit 506d343843
460 changed files with 0 additions and 108428 deletions
Download Patch File Download Diff File Expand all files Collapse all files

61
23-descriptor/bulkfood/bulkfood_v3.py
View File

@@ -1,61 +0,0 @@
"""
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
Negative or 0 price is not acceptable either::
>>> truffle = LineItem('White truffle', 100, 0)
Traceback (most recent call last):
...
ValueError: value must be > 0
No change was made::
>>> raisins.weight
10
"""
# BEGIN LINEITEM_V3
class Quantity: # <1>
def __init__(self, storage_name):
self.storage_name = storage_name # <2>
def __set__(self, instance, value): # <3>
if value > 0:
instance.__dict__[self.storage_name] = value # <4>
else:
raise ValueError('value must be > 0')
class LineItem:
weight = Quantity('weight') # <5>
price = Quantity('price') # <6>
def __init__(self, description, weight, price): # <7>
self.description = description
self.weight = weight
self.price = price
def subtotal(self):
return self.weight * self.price
# END LINEITEM_V3

74
23-descriptor/bulkfood/bulkfood_v4.py
View File

@@ -1,74 +0,0 @@
"""
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) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
['_Quantity#0', '_Quantity#1', '__class__', ...
'description', 'price', 'subtotal', 'weight']
>>> getattr(raisins, '_Quantity#0')
10
>>> getattr(raisins, '_Quantity#1')
6.95
"""
# BEGIN LINEITEM_V4
class Quantity:
__counter = 0 # <1>
def __init__(self):
cls = self.__class__ # <2>
prefix = cls.__name__
index = cls.__counter
self.storage_name = '_{}#{}'.format(prefix, index) # <3>
cls.__counter += 1 # <4>
def __get__(self, instance, owner): # <5>
return getattr(instance, self.storage_name) # <6>
def __set__(self, instance, value):
if value > 0:
setattr(instance, self.storage_name, value) # <7>
else:
raise ValueError('value must be > 0')
class LineItem:
weight = Quantity() # <8>
price = 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_V4

85
23-descriptor/bulkfood/bulkfood_v4b.py
View File

@@ -1,85 +0,0 @@
"""
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) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
['_Quantity#0', '_Quantity#1', '__class__', ...
'description', 'price', 'subtotal', 'weight']
>>> getattr(raisins, '_Quantity#0')
10
>>> getattr(raisins, '_Quantity#1')
6.95
If the descriptor is accessed in the class, the descriptor object is
returned:
>>> LineItem.weight # doctest: +ELLIPSIS
<bulkfood_v4b.Quantity object at 0x...>
>>> LineItem.weight.storage_name
'_Quantity#0'
"""
# BEGIN LINEITEM_V4B
class Quantity:
__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 # <1>
else:
return getattr(instance, self.storage_name) # <2>
def __set__(self, instance, value):
if value > 0:
setattr(instance, self.storage_name, value)
else:
raise ValueError('value must be > 0')
# END LINEITEM_V4B
class LineItem:
weight = Quantity()
price = Quantity()
def __init__(self, description, weight, price):
self.description = description
self.weight = weight
self.price = price
def subtotal(self):
return self.weight * self.price

65
23-descriptor/bulkfood/bulkfood_v4c.py
View File

@@ -1,65 +0,0 @@
"""
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) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
['_Quantity#0', '_Quantity#1', '__class__', ...
'description', 'price', 'subtotal', 'weight']
>>> getattr(raisins, '_Quantity#0')
10
>>> getattr(raisins, '_Quantity#1')
6.95
If the descriptor is accessed in the class, the descriptor object is
returned:
>>> LineItem.weight # doctest: +ELLIPSIS
<model_v4c.Quantity object at 0x...>
>>> LineItem.weight.storage_name
'_Quantity#0'
"""
# BEGIN LINEITEM_V4C
import model_v4c as model # <1>
class LineItem:
weight = model.Quantity() # <2>
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_V4C

74
23-descriptor/bulkfood/bulkfood_v4prop.py
View File

@@ -1,74 +0,0 @@
"""
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) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
[... '_quantity:0', '_quantity:1', 'description',
'price', 'subtotal', 'weight']
>>> getattr(raisins, '_quantity:0')
10
>>> getattr(raisins, '_quantity:1')
6.95
"""
# BEGIN LINEITEM_V4_PROP
def quantity(): # <1>
try:
quantity.counter += 1 # <2>
except AttributeError:
quantity.counter = 0 # <3>
storage_name = '_{}:{}'.format('quantity', quantity.counter) # <4>
def qty_getter(instance): # <5>
return getattr(instance, storage_name)
def qty_setter(instance, value):
if value > 0:
setattr(instance, storage_name, value)
else:
raise ValueError('value must be > 0')
return property(qty_getter, qty_setter)
# END LINEITEM_V4_PROP
class LineItem:
weight = quantity()
price = quantity()
def __init__(self, description, weight, price):
self.description = description
self.weight = weight
self.price = price
def subtotal(self):
return self.weight * self.price

79
23-descriptor/bulkfood/bulkfood_v5.py
View File

@@ -1,79 +0,0 @@
"""
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) # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
['_NonBlank#0', '_Quantity#0', '_Quantity#1', '__class__', ...
'description', 'price', 'subtotal', 'weight']
>>> getattr(raisins, '_Quantity#0')
10
>>> getattr(raisins, '_NonBlank#0')
'Golden raisins'
If the descriptor is accessed in the class, the descriptor object is
returned:
>>> LineItem.weight # doctest: +ELLIPSIS
<model_v5.Quantity object at 0x...>
>>> LineItem.weight.storage_name
'_Quantity#0'
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_V5
import model_v5 as model # <1>
class LineItem:
description = model.NonBlank() # <2>
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_V5

85
23-descriptor/bulkfood/bulkfood_v5_check.py
View File

@@ -1,85 +0,0 @@
"""
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

23
23-descriptor/bulkfood/model_v4c.py
View File

@@ -1,23 +0,0 @@
# BEGIN MODEL_V4
class Quantity:
__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):
if value > 0:
setattr(instance, self.storage_name, value)
else:
raise ValueError('value must be > 0')
# END MODEL_V4

54
23-descriptor/bulkfood/model_v5.py
View File

@@ -1,54 +0,0 @@
# BEGIN MODEL_V5
import abc
class AutoStorage: # <1>
__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) # <2>
class Validated(abc.ABC, AutoStorage): # <3>
def __set__(self, instance, value):
value = self.validate(instance, value) # <4>
super().__set__(instance, value) # <5>
@abc.abstractmethod
def validate(self, instance, value): # <6>
"""return validated value or raise ValueError"""
class Quantity(Validated): # <7>
"""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 # <8>
# END MODEL_V5

52
23-descriptor/bulkfood/model_v5_check.py
View File

@@ -1,52 +0,0 @@
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