aDict = {'key1':'value1', 'key2':'value2', 'key3':'value3'}
print '-----------dict-------------'
for d in aDict:
  print "%s:%s" %(d, aDict[d])

print '-----------item-------------'
for (k,v) in aDict.items():
  print '%s:%s' %(k, v)

#效率最高

print '------------iteritems---------'
for k,v in aDict.iteritems():
  print '%s:%s' % (k, v)

#最笨的方法

print '---------iterkeys---------------'
for k in aDict.iterkeys():
  print '%s:%s' % (k, aDict[k])

print '------------iterkeys, itervalues----------'
for k,v in zip(aDict.iterkeys(), aDict.itervalues()):
  print '%s:%s' % (k, v)

<pre name="code" class="python">-----------dict-------------
key3:value3
key2:value2
key1:value1
-----------item-------------
key3:value3
key2:value2
key1:value1
------------iteritems---------
key3:value3
key2:value2
key1:value1
---------iterkeys---------------
key3:value3
key2:value2
key1:value1
------------iterkeys, itervalues----------
key3:value3
key2:value2
key1:value1