Did you have thought?of the questions as following:

1. When and where to use?Enum?

2. Why do we need?Enum? What are the advantages?

3. What exactly is an?Enum?

Let's talk about the qustions that already answered respectively.

1. When and where to use enums?

• When you have a variable that takes one of a limited set of possible values.

For example, the days of the week:

2. Why do we need enum? What are the advantages?

• Enums are advantageous because they give a name to a constant, which makes code more readable; and because the individual members cannot be rebound, making Python Enums semi-constant (because the?Enum?itself could still be rebound).

• Besides more readable code, debugging is also easier as you see a name along with the value, not just the value

• Desired behavior can be added to Enums

For example, as anyone who has worked with the?datetime?module knows,?datetime?and?date?have two different representations for the days of the week: 0-6 or 1-7. Rather than keep track of that ourselves we can add a method to the?Weekday?enum to extract the day from the?datetime?or?date?instance and return the matching enum member:

3. What exactly is Enum?

• Enum is a?type, whose members are named constants, that all belong to (or should) a logical group of values. So far I have created?Enums for:

FederalHoliday?is my most complex; it uses?this recipe, and has methods to return the actual date the holiday takes place on for the year given, the next business day if the day in question is a holiday (or the range of days skipped includes the holiday or weekends), and the complete set of dates for a year. Here it is:

本文轉(zhuǎn)自stackoverflow，希望對你有所幫助。

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