1. 程式人生 > >python Class:面向對象高級編程 Enum(枚舉)、@unique

python Class:面向對象高級編程 Enum(枚舉)、@unique

ret value word 內容 pytho blog rec rate 如果

註:python 3.x版本才能使用

枚舉格式:

from enum import Enum

新類名 = Enum(變量統稱名,(變量1,變量2....))

Month = Enum('month', ('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'))


1.

seasons = ['Spring', 'Summer', 'Fall', 'Winter']
print (list(enumerate(seasons)))

運行結果:

[(0, 'Spring'), (1, 'Summer'), (2, 'Fall'), (3, 'Winter')]


2.

from enum import Enum

Month = Enum('month', ('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'))

for name, member in Month.__members__.items():
    print(name, '=>', member, ',', member.value)

運行結果:

Jan => month.Jan , 1
Feb => month.Feb , 2
Mar => month.Mar , 3
Apr => month.Apr , 4
May => month.May , 5
Jun => month.Jun , 6
Jul => month.Jul , 7
Aug => month.Aug , 8
Sep => month.Sep , 9
Oct => month.Oct , 10
Nov => month.Nov , 11
Dec => month.Dec , 12


3. 當Class中有重復值時,會返回第一個,其他忽略

from enum import Enum

class Weekday(Enum):
    monday = 1
    tusday = 1
    wensdday =3
    thursday =9
    friday =5
#print (Weekday(1))

for n in Weekday:
    print (n)

運行結果:

Weekday.monday
Weekday.wensdday
Weekday.thursday
Weekday.friday

手動打Enum值時,一不小心打錯了怎麽辦,又得一個個找,真麻煩。所以,有人想,如果有個方法能夠檢查重復值就好了,於是:@unique就出來了

from enum import Enum, 
@unique
class Weekday(Enum):
    monday = 1
    tusday = 1
    wensdday =3
    thursday =9
    friday =5
print (Weekday(1)

運行結果:

Traceback (most recent call last):
  File "/usercode/file.py", line 7, in <module>
    class Weekday(Enum):
  File "/usr/lib/python3.4/enum.py", line 524, in unique
    (enumeration, alias_details))


4.有人也在想,我就是不改咋地!我能不能通過另一個方法把成員都打印出來?於是:__members__就出來了

from enum import Enum

class Weekday(Enum):
    monday = 1
    tusday = 1
    wensdday = 3
    thursday = 9
    friday = 5

for n,y in Weekday.__members__.items():
    print (n, '--', y, '--',  y.value)
    
f = Weekday.thursday
print (f.value)

運行結果:

monday -- Weekday.monday -- 1
tusday -- Weekday.tusday -- 1
wensdday -- Weekday.wensdday -- 3
thursday -- Weekday.thursday -- 9
friday -- Weekday.friday -- 5
9

5.枚舉比較:不能比大小!!能比同值

from enum import Enum, unique

#@unique
class Weekday(Enum):
    monday = 1
    tusday = 1
    wensdday =3
    thursday =9
    friday =5

print (Weekday.monday == Weekday.wensdday)
print (Weekday.tusday is Weekday.friday )

print (Weekday.tusday > Weekday.friday )

運行結果:

False
False

Traceback (most recent call last):
  File "/usercode/file.py", line 16, in <module>
    print (Weekday.tusday > Weekday.friday )
TypeError: unorderable types: Weekday() > Weekday()



看到一個很好很好的Blog,這講的內容,他的比廖某的還要簡潔明了。很喜歡。我的怎麽亂?我純粹是做筆記,沒想那麽多,要改構造想多了反而浪費時間。

https://blog.csdn.net/xionghuixionghui/article/details/66476601

python Class:面向對象高級編程 Enum(枚舉)、@unique