擅长:python、mysql、java
<p>下面是一个调整数据类型以接受外部属性的示例:</p>
<pre><code>class unicode (__builtins__.unicode):
def __new__ (cls, u=""):
self = __builtins__.unicode.__new__(cls, u)
return self
# So, you do it just once and then you can:
def add_check (obj):
obj.IsNullOrEmpty = lambda: not obj
u1 = unicode("12345")
u2 = unicode()
add_check(u1)
add_check(u2)
print u1.IsNullOrEmpty()
print u2.IsNullOrEmpty()
</code></pre>
<p>注:使用:</p>
<pre><code>u3 = u'1234'
</code></pre>
<p>将产生<strong>内置的</strong>.unicode(),而不是我们修改过的类型,因此您必须是显式的</p>