with上下文管理器
http://blog.****.net/Shiroh_ms08/article/details/53859475
# 玩with语句
class TestWith(object):
def __init__(self):
print("this is init of TestWith")
def if_exist(self):
print("I'm here")
def __enter__(self):
print("This is TestWith __enter__")
return self
def __exit__(self, *args):
for i in args:
print(i)
print("Now __exit__")
with TestWith() as t:
t.if_exist()