unpack (iterable, count, fill=None)

参数:

iterable: 实现 __iter__的可迭代对象, 如 str, tuple, dict, list

count:    需要拆分的数量, 如数值大于 len(iterable) 则使用 fill 的值进行后续填充

fill:          默认值填充

使用范例:

Example 1:        In[1]: source = 'abc'        In[2]: a, b = unpack(source, 2)        In[3]: print(a, b)        a bExample 2:        In[1]: source = 'abc'        In[2]: a, b, c, d = unpack(source, 4)        In[3]: print(a, b, c, d)        a b None None

 

代码:

@(iterable='__iter__', count=int)def unpack(iterable, count, fill=None):    """    The iter data unpack function.    """    iterable = list(enumerate(iterable))    cnt = count if count <= len(iterable) else len(iterable)    results = [iterable[i][1] for i in range(cnt)]    # results[len(results):len(results)] = [fill for i in range(count-cnt)]    results = (results, [fill for i in range(count-cnt)])    return tuple(results)