Python笔记（八）-语句

Python语句

语句	角色	例子
yield	生成器函数	def gen(n): for i in n: yield i*2
global	命名空间	x = ‘old’ def function():global x,y;x=’new’
nonlocal	Namespaces命名空间	def outer(): x=’old’ def function():nonlocal x;x = ‘new’
try/except/finally	捕捉异常	try: action() except: print(‘action error’)
raise	触发异常	raise EndSearch(location)
assert	调试检查	assert X>Y,’X too small’
with/as	环境管理器	with open(‘data’) as myfile: process(myfile)

交互循环实例

交互式循环

>>> while True:
...     reply = input('Enter text:')
...     if reply == 'stop': break
...     print(reply.upper())
... 
Enter text:hello
HELLO
Enter text:hi
HI
Enter text:stop
>>>

输入数据做数学运算

>>> while True:
...     reply = input('Enter text:')
...     if reply == 'stop':break
...     print(int(reply) ** 2)
... 
Enter text:24
576
Enter text:34
1156