遍历字典

• 遍历字典key值

  a = {'a': '1', 'b': '2', 'c': '3'}
  for i in a.keys():
      print(i)
  ## y与下面代码等价
  for i in a:
      print(i)
  

• 遍历字典value值

  a = {'a': '1', 'b': '2', 'c': '3'}
  for value in a.values():
      print(value)
  

• 遍历字典项

  for kv in a.items():
         print(kv)
          # kv是元祖
  

• 遍历字典键值

  for key,value in a.items():
         print(key+':'+value)