How would you translate this from Perl to Python?

Question

I\'ve got a Perl function which takes a timestamp and returns either the unchanged timestamp (if it\'s never seen it before) or otherwise, it appends some letters to make it uni

Answer 1

Looking at the problem it seems like a good fit for a coroutine (Python 2.5 or higher). Here's some code that will roughly produce the same result:

def uniqify():
    seen = {}
    val = (yield None)
    while True:
        if val in seen:
            idxa, idxb = seen[val]
            idxb += 1
        else:
            idxa, idxb = (len(seen)+1, ord('a'))
        seen[val] = (idxa, idxb)
        uniq = "%s%s" % (idxa, chr(idxb))
        val = (yield uniq)

And here's how you use it:

>>> u = send.uniqify()
>>> u.next() #need this to start the generator
>>> u.send(1)
'1a'
>>> u.send(1)
'1b'
>>> u.send(1)
'1c'
>>> u.send(2)
'2a'
>>> u.send(2)
'2b'
>>> u.send(1) #you can go back to previous values
'1d'
>>> u.send('stringy') #you can send it anything that can be used as a dict key
'3a'