Question

我知道已经数次问过类似问题。现在,我是如何利用搜索功能的,但它仍然不可行。

因此,这里的问题是问题。我有一份名单,其中载有插图。一栏载有实际上代表浮动价值的说明。这也是一栏希望按顺序排列。问题在于, p似乎忽略了——(名)在条目上签字。例如:

[[blaa,  0.3 , bli], [bla,  0.1 , blub], [bla,  -0.2 , blub]]

类似情况:

[[bla,  0.1 , blub], [bla,  -0.2 , blub], [blaa,  0.3 , bli]]

而不是应该如何:

[[bla,  -0.2 , blub],[bla,  0.1 , blub], [blaa,  0.3 , bli]]

至今:

casting the second column to float and sorting by that column

如:

for i in mylist:
  i[1] = float(i[1])    

mylist.sort(key=lambda x: x[1])

或

for i in mylist:
  i[1] = float(i[1]) 

mylist.sort(key=operator.itemgetter(1))

I also tried to define my own compare function:

如:

mylist.sort(cmp=lambda x,y: cmp(float(x), float(y)), key=operator.itemgetter(1))

以上方法的任何其它组合,也与<代码>d/code>相同。迄今为止,没有成功, minu子的信号总是被忽视。如何解决这一问题?

[edit] Also already tried the Ignacio suggestion. I should mention i HAVE to use python 2.5 .

Answer 1

l = [["blaa", "0.3", "bli"], ["bla", "0.1", "blub"], ["bla", "-0.2", "blub"]]

l.sort(key=lambda x: float(x[1]))

>>> [[ bla ,  -0.2 ,  blub ], [ bla ,  0.1 ,  blub ], [ blaa ,  0.3 ,  bli ]]

Answer 2

3.1.2:

>>> l=[[  ,  0.3 ,   ], [  ,  0.1 ,   ], [  ,  -0.2 ,   ]]
>>> sorted(l,key=lambda x:float(x[1]))
[[  ,  -0.2 ,   ], [  ,  0.1 ,   ], [  ,  0.3 ,   ]]

页: 1

>>> l=[[  ,  0.3 ,   ], [  ,  0.1 ,   ], [  ,  -0.2 ,   ]]
>>> sorted(l,key=lambda x:float(x[1]))
[[  ,  -0.2 ,   ], [  ,  0.1 ,   ], [  ,  0.3 ,   ]]

友情链接