需求：遍历字典时，删除某个
key
正常情况下是不能直接删除的，需要借助其他方式：
# coding=utf-8
data = {"name": "rose", "age": 19}
# 遍历字典并删除某个 key
# 报错：RuntimeError: dictionary changed size during iteration
for k, v in data.items():
if k == "name":
data.pop(k)
优化后：
print(list(data.items())) # [('name', 'rose'), ('age', 19)]
for k, v in list(data.items()):
if k == "name":
data.pop(k)
print(data)
