python join equivalent

Question

I have a dictionary say..

dict = {
    'a' : 'b',
    'c' : 'd'
}

In php I would to something like implode ( ',', $dict ) and get the output 'a,b,c,d' How do I do that in python?

Answer 1

This seems to be easiest way:

>>> from itertools import chain
>>> a = dict(a='b', c='d')
>>> ','.join(chain(*a.items()))
'a,b,c,d'

Answer 2

First, the wrong answer:

','.join('%s,%s' % i for i in D.iteritems())

This answer is wrong because, while associative arrays in PHP do have a given order, dictionaries in Python don't. The way to compensate for that is to either use an ordered mapping type (such as OrderedDict), or to force an explicit order:

','.join('%s,%s' % (k, D[k]) for k in ('a', 'c'))