Python： 遍歷

======================遍歷列表========================
# 直接遍歷list：

for elem in list:
     pass

# 通過索引獲取

for i in range(len(list)):
     elem = list[i]
     pass

# 基於enumerate()遍歷

for i, elem in enumerate(list):
     pass

# 基於iter()遍歷

listIter = iter(list)
while True:
     try:
          elem = listIter.next()
          # ....
     expect StopIteration, ex:
          // NOOP

=====================遍歷dict==========================
# 通過key遍歷

for key in dict.keys():
     value = dict.get(key)
     pass

# 直接遍歷，本質是先轉換成 (key,value)的list

for key,value in dict.items():
     pass

# iteritems() 返回值是 items的迭代器

for key,value in dict.iteritems():
     pass