CODEWITHSUNDEEP
python
Xolve
Xolve

Reputation: 23200

Add event to list

I want to add event to list such that on adding items actions are taken based on the item e.g. genrating new data structures, change in screen output or raising exception.

How do I accomplish this?

Upvotes: 2

Views: 1420

Answers (1)

Jason Coon
Jason Coon

Reputation: 18431

You could create your own class that extends the list object:

class myList(list):
    def myAppend(self, item):
        if isinstance(item, list):
            print 'Appending a list'
            self.append(item)
        elif isinstance(item, str):
            print 'Appending a string item'
            self.append(item)
        else:
            raise Exception

L = myList()
L.myAppend([1,2,3])
L.myAppend('one two three')
print L

#Output:
#Appending a list
#Appending a string item
#[[1, 2, 3], 'one two three']

Upvotes: 1

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