StringIO类的用途

import StringIO as SIO


s1 = "Hello"
print id(s1)
s2 = "Hello" + s1
print id(s2)
sp = SIO.StringIO()
sp.write("Hello")
print sp.getvalue()
print id(sp)
sp.write("Leon")
print sp.getvalue()
print id(sp)
exit()

 主要进行字符串数据缓存，以便循环利用