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pythonlistlist-comprehensionenumerate

Increment or index value for list comprehensions?

Is there a handy way to get an autoincrement or index into a list comprehension? I’m trying to build a list of objects, each of which needs a unique identifier. So instead of this:

tags_list = ['art', 'science', 'lollipops']

class Tag:
    def __init__(self, id, name):
        self.id = id
        self.name = name

tags = []    
i = 1
for t in tags_list:
    tag = Tag(i, t)
    tags.append(tag)
    i += 1

…something like this:

tags = [Tag(i, t) for t in tags_list]

^^^ how do I get i?

I know about enumerate() but this gives me tuples right?

Solution 
  • tags = [Tag(i, t) for i,t in enumerate(tags_list, 1)]