tensorflow,tf.while_loop:这两个结构没有相同的嵌套结构

时间:2019-04-02 23:20:57

标签: python tensorflow deep-learning

我试图建立一个嵌套循环,该循环用于创建2维零矩阵来解决LCS问题(动态编程)。稍后将其用于计算Rouge-L得分(输入是张量,而不是字符串),但是提高ValueError: The two structures don't have the same nested structure.

总是会出错。

我检查了一些类似的问题,并修改了一些代码,但仍然无法正常工作(我在此处输入的代码是最终代码):

  1. 我更改了shape_invariants。我现在使用len(inner)动态获取inner的形状。
  2. 仍然使用shape_invariants,现在我将1更改为0(shape_invariants中的第一个参数)。我以为标量的形状是1,但是我在github上检查了一些源代码,发现它们都使用0。

# the origin code is below, in which sub and string are both string(type), len_sub and len_string are both int:

lengths = [[0 for i in range(0,len_sub+1)] for j in range(0,len_string+1)]

# but in the new code that I need, the sub and string are both tensor, so I code like this:

len_string = tf.shape(string)[0]
len_sub = tf.shape(sub)[0]

def _add_zeros(i,inner):
        inner.append(0)
        return i+1, inner
def _add_inners(j, lengths):
    i=0
    inner = []
    _, inner = tf.while_loop(
                cond=lambda i,*_: i<=len_sub,
                body=_add_zeros,
                loop_vars=[i,inner],
                shape_invariants=[0,len(inner)])
    lengths.append(inner)
    return j+1, lengths

lengths = []
j = 0  
_, lengths = tf.while_loop(
                cond=lambda j,*_: j<=len_string,
                body=_add_inners,
                loop_vars=[j,lengths],
                shape_invariants=[0,len(lengths)])
ValueError: The two structures don't have the same nested structure.  
First structure: type=list str=[0, []]  
Second structure: type=list str=[0, 0]  
More specifically: Substructure "type=list str=[]" is a sequence, while substructure "type=int str=0" is not  
Entire first structure:  
[., []]  
Entire second structure:  
[., .]  

我不知道为什么会出错。如果您能提供帮助,我将不胜感激。

1 个答案:

答案 0 :(得分:0)

嗨,基本上,错误消息的意思是您的返回值是一个列表,而它期望它是一个数字,这很有意义,因为您已将shape_invariant定义为[0, len(lengths)],它们都是整数,因此第二个结构定义为[.,.],但是第一个结构是一个数字和一个列表[., []],当您传递长度时,列表shape_invariants=[0,len(lengths)])再次有意义。

TLDR:将shape_invariants=[0,lengths])更改为loop_vars=[j,lengths]或将loop_vars=[j,len(lengths)],更改为SELECT c.symbol, c.number, c.sectionNumber FROM courseoffering_of c INNER JOIN location l ON l.building = c.building AND l.room = c.room INNER JOIN enrolled e ON e.number = c.number AND e.sectionNumber = c.sectionNumber GROUP BY c.symbol, c.number, c.sectionNumber, l.capacity HAVING count(*) >= l.capacity