如何通过第二个键将列表搜索到嵌套列表中并将其附加到另一个列表中？

Question

Here is given a nested list:

nl=[['Tina', 37.2], ['Harry', 37.21], ['Berry', 37.21], ['Harsh', 39], ['Akriti', 41]]

Now I have to search for the lists which second value is 37.21. Those lists which second value get matched with 37.21, will be appended into another list.

So the output should be:

['Harry', 37.21], ['Berry', 37.21]

How do I do it?

Answer 1

You iterate over the whole list nl and extract the value at the second index of the nested lists and compare it with the desired value , if it matches then you simply append the nested list to another list answer

nl=[['Tina', 37.2], ['Harry', 37.21], ['Berry', 37.21], ['Harsh', 39], ['Akriti', 41]]        

answer = []

for sample_list in nl:
    if sample_list[1]==37.21:
        answer.append(sample_list)
print answer
>>> [['Harry', 37.21], ['Berry', 37.21]]

Answer 2

You can use list comprehension:

 [l for l in nl if l[1] == 37.21]

which returns

[['Harry', 37.21], ['Berry', 37.21]]