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Lets's say I have an enumerator, is it possible to get the property that follows? So if I had today=Days.Sunday would I be able to do something like tomorrow=today.next()?
example:
class Days(Enum):
Sunday = 'S'
Monday = 'M'
...
Saturday = 'Sa'
I know I could use tuples (like below) to do something like tomorrow=today[1], but I was hoping there was something built in or more elegant.
class Days(Enum):
Sunday = ('S','Monday')
Monday = ('M','Tuesday')
...
Saturday = ('Sa','Sunday')
594
Enum. GetName(Type, Object) Method is used to get the name of the constant in the specified enumeration that has the specified value. Syntax: public static string GetName (Type enumType, object value);
auto() method, we can get the assigned integer value automatically by just using enum. auto() method. Syntax : enum.auto() Automatically assign the integer value to the values of enum class attributes.
You do not instantiate an enum , but rely the constants defined. Enums can be used in a switch-case statement, just like an int .
An enumeration type (or enum type) is a value type defined by a set of named constants of the underlying integral numeric type. To define an enumeration type, use the enum keyword and specify the names of enum members: C# Copy.
Absolutely.
Just add the desired functionality to your Days class:
class Days(Enum):
Sunday = 'S'
Monday = 'M'
Tuesday = 'T'
Wednesday = 'W'
Thursday = 'Th'
Friday = 'F'
Saturday = 'Sa'
def next(self):
cls = self.__class__
members = list(cls)
index = members.index(self) + 1
if index >= len(members):
index = 0
return members[index]
and in use:
today = Days.Wednesday
print(today.next())
# Days.Thursday
While the above is probably easier to understand, it is possible to do the work once in __init__ by adding a next attribute to each member (and previous while we're at it).
class Days(Enum):
#
Sunday = 'S'
Monday = 'M'
Tuesday = 'T'
Wednesday = 'W'
Thursday = 'Th'
Friday = 'F'
Saturday = 'Sa'
#
def __init__(self, value):
if len(self.__class__):
# make links
all = list(self.__class__)
first, previous = all[0], all[-1]
previous.next = self
self.previous = previous
self.next = first
and in use:
>>> Days.Tuesday.next
<Days.Wednesday: 'W'>
>>> Days.Tuesday.previous
<Days.Monday: 'M'>
>>> Days.Saturday.next
<Days.Sunday: 'S'>
>>> Days.Saturday.previous
<Days.Friday: 'F'>
NB Using the this method of attributes means we no longer need the ()s after next/previous.
150
You can create a dictionary to lookup the next day like so:
In [10]: class Days(Enum):
Sun = 'Su'
Mon = 'M'
Tue = 'Tu'
Wed = 'W'
Thu = 'Th'
Fri = 'F'
Sat = 'Sa'
In [11]: days = list(Days)
In [12]: nxt = dict((day, days[(i+1) % len(days)]) for i, day in enumerate(days))
Quick test:
In [13]: nxt[Days.Tue]
Out[13]: <Days.Wed: 'W'>
In [14]: nxt[Days.Sat]
Out[14]: <Days.Sun: 'Su'>
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