在python中订购枚举值 [英] Ordering enum value in python
问题描述
pre>类型):
def __new __(typ,name,bases,attrs):
cls_attrs = {}
cls_choices = []
for attr_name,attrs.items()中的值:
cls_attrs [attr_name] = attr_name.lower()
如果不是attr_name.startswith(__):
cls_choices.append((attr_name.lower(),value))
def choice(cls):
return cls_choices
def values(cls,value = None):
如果值为None:
return {选择[0]:unicode(选择[1])在cls.choices()中的选择}
elif isinstance(value,list):
return {choice [0]:unicode(choice [1] )选择cls.choices()如果选择[0]在值}
else:
返回unicode(dict(cls.choices())。get(value))
def键(cls,nil = False):
它ems = [item [0] for clschoices()]
if nil:
items.append('')
返回项目
def combined_length(cls):
return len(,。join(cls.values()。keys()))
def max_length(cls):
return max(map(len,cls.values()。keys()))
cls_attrs ['choices'] = classmethod(choices)
cls_attrs ['values'] = classmethod值)
cls_attrs ['keys'] = classmethod(keys)
cls_attrs ['combined_length'] = classmethod(combine_length)
cls_attrs ['max_length'] = classmethod(max_length)
返回类型(名称,基数,cls_attrs)
枚举的一个例子是如下:
class SideHemType:
__ordering__ = ['double','single']
__metaclass__ = EnumMeta
Single =不透明面料单面下摆
Double =透明面料双面边框
class TestEnumOrdering:
print SideHemType.keys()
print SideHemType.values()
通过打印Enum SideHemType,首先打印Double,然后单击。但我想要先单,然后双。
您的枚举在3个地方失去了排序。首先,类体上的属性存储在字典中,然后将项目复制到另一个字典中。最后,你的 values()
返回第3个字典。字典不保存排序,并且不可能在类体内获取属性的排序。
使用此系统最简单的方法是使变量
__ ordering__ = ['single','double']
并使 values()
返回一个元组列表(如 dict.items()
)
class EnumMeta(type):
def __new __(typ,name, ,attrs):
cls_attrs = {}
cls_choices = {}
$ b对于attr_name,attrs.items()中的值:
cls_attrs [attr_name] = attr_name。 lower()
如果不是attr_name.startswith(__):
cls_choices [attr_name.lower()] = value
ordering = attrs.get('__ ordering__')
如果订购==无:
订购=排序(cls_choices.keys())
定义选择(cls):
返回dict(cls_choices)
def值(cls,value = None):
如果值为None:
返回[(k,cls_choices [k])for k在排序]
elif not isinstance(value,basestring):
return [(k,cls_choices [k])for k in value]
else:
return unicode(cls_choices.get(value))
def key(cls,nil = False):
items = list(ordering)
如果nil:
items.append('')
返回项目
def combined_length(cls):
return len(,。join(cls.values()。keys()))
def max_length (cls):
return max(map(len,cls.values()。keys()))
cls_attrs ['choices'] = classmethod(choices)
cls_attrs ['values'] = classmethod(values)
cls_attrs ['keys'] = classmethod(keys)
cls_attrs ['combined_length'] = classmethod _length)
cls_attrs ['max_length'] = classmethod(max_length)
返回类型(name,bases,cls_attrs)
class SideHemType:
__ordering__ = ['double','single']
__metaclass__ = EnumMeta
Single =不透明面料的单面下摆
Double =透明面料的双面下摆
打印SideHemType.keys()
打印SideHemType.values()
I would like to be able to arrange the ordering of Enum. Has somebody suggestions how this can be solved?
The following Enum meta class is using:
class EnumMeta(type):
def __new__(typ, name, bases, attrs):
cls_attrs = {}
cls_choices = []
for attr_name, value in attrs.items():
cls_attrs[attr_name] = attr_name.lower()
if not attr_name.startswith("__"):
cls_choices.append((attr_name.lower(), value))
def choices(cls):
return cls_choices
def values(cls, value=None):
if value is None:
return {choice[0]: unicode(choice[1]) for choice in cls.choices()}
elif isinstance(value, list):
return {choice[0]: unicode(choice[1]) for choice in cls.choices() if choice[0] in value}
else:
return unicode(dict(cls.choices()).get(value))
def keys(cls, nil=False):
items = [item[0] for item in cls.choices()]
if nil:
items.append('')
return items
def combined_length(cls):
return len(",".join(cls.values().keys()))
def max_length(cls):
return max(map(len, cls.values().keys()))
cls_attrs['choices'] = classmethod(choices)
cls_attrs['values'] = classmethod(values)
cls_attrs['keys'] = classmethod(keys)
cls_attrs['combined_length'] = classmethod(combined_length)
cls_attrs['max_length'] = classmethod(max_length)
return type(name, bases, cls_attrs)
An example of an Enum is as follow:
class SideHemType:
__ordering__ = ['double', 'single']
__metaclass__ = EnumMeta
Single = "Single side hem for opaque fabrics"
Double = "Double side hem for transparent fabrics"
class TestEnumOrdering:
print SideHemType.keys()
print SideHemType.values()
By printing the Enum SideHemType first Double is printed and then Single. But I would like first Single and then Double.
Your Enum loses the ordering in 3 places. First the attributes on the class body are stored in a dictionary, then you copy the items into another dictionary. Finally your values()
returns a 3rd dictionary. A dictionary does not save ordering, and it is impossible to get the ordering of the attributes within the class body.
With this system the easiest is to have a variable
__ordering__ = [ 'single', 'double' ]
And make the values()
return a list of tuples (like dict.items()
).
class EnumMeta(type):
def __new__(typ, name, bases, attrs):
cls_attrs = {}
cls_choices = {}
for attr_name, value in attrs.items():
cls_attrs[attr_name] = attr_name.lower()
if not attr_name.startswith("__"):
cls_choices[attr_name.lower()] = value
ordering = attrs.get('__ordering__')
if ordering == None:
ordering = sorted(cls_choices.keys())
def choices(cls):
return dict(cls_choices)
def values(cls, value=None):
if value is None:
return [ (k, cls_choices[k] ) for k in ordering ]
elif not isinstance(value, basestring):
return [ (k, cls_choices[k] ) for k in value ]
else:
return unicode(cls_choices.get(value))
def keys(cls, nil=False):
items = list(ordering)
if nil:
items.append('')
return items
def combined_length(cls):
return len(",".join(cls.values().keys()))
def max_length(cls):
return max(map(len, cls.values().keys()))
cls_attrs['choices'] = classmethod(choices)
cls_attrs['values'] = classmethod(values)
cls_attrs['keys'] = classmethod(keys)
cls_attrs['combined_length'] = classmethod(combined_length)
cls_attrs['max_length'] = classmethod(max_length)
return type(name, bases, cls_attrs)
class SideHemType:
__ordering__ = ['double', 'single']
__metaclass__ = EnumMeta
Single = "Single side hem for opaque fabrics"
Double = "Double side hem for transparent fabrics"
print SideHemType.keys()
print SideHemType.values()
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