1.循环打印字典：
1 a = {‘a‘: 1, ‘b‘: 2} 2 for k in a: 3 print a[k]
还有另外一种，但是不够简洁
1 a = {‘a‘: 1, ‘b‘: 2} 2 for k in a.keys(): 3 print a[k]
2.循环符合条件删除：
1 a = {‘a‘: 1, ‘b‘: 2} 2 for k in a: 3 if k == ‘a‘: 4 del a[k] 5 6 print a
但是会出错：RuntimeError: dictionary changed size during iteration
如果这样：
1 a = {‘a‘: 1, ‘b‘: 2} 2 for k in a.keys(): 3 if k == ‘a‘: 4 del a[k] 5 6 print a
就会没事
暂且留意下。。。
原文：http://www.cnblogs.com/Alex-LiN/p/5197767.html