isinstance(data,int)
isinstance(data,list)
isinstance(data,dict)
isinstance(data,float)
type(a)==list
type(a) is list
type(a)==int
type(a) is int
type(a)==type(1)
type(a)==type([])
type(a)==type()
第一种是if x is None;
第二种是 if not x:
第三种是if x is not None