Multiple Assignment with Dictionaries

Combining built in function items to transform dictionary into a list of tuples, tuple assignment and for loop you can create nice code pattern for traversing the keys and values of a dictionary in a single loop.

d = {'a':10, 'b':20, 'c': 30}
l = list()
for key,val in d.items():
    print key, val
    l.append((key,val))
print "l = " + str(l)
l.sort(reverse = True)
print "List of tuples after applying sort()function"
print "l = " + str(l)

Output of previous code is given below.

a 10
c 30
b 20
l = [('a', 10), ('c', 30), ('b', 20)]

List of tuples after applying sort()function

l = [('c', 30), ('b', 20), ('a', 10)]

The for loop has two iteration variable because items returns a list of tuples and key, val is a tuple assignment that successively iterates through each of the key/value pairs in the dictionary. For each iteration through the loop, both key and value are advanced to the next key/value pair in the dictionary.