Here is given a nested list:
nl = [['Harsh', 20], ['Beria', 20], ['Varun', 19], ['Kakunami', 19], ['Vikas', 21]]
Now I have to find the second lowest lists into the nested list by their second value. And append the second lowest lists into another list.
So the output should be:
['Harsh', 20], ['Beria', 20]
I wrote the following code but it doesn’t work:
nl = [['Harsh', 20], ['Beria', 20], ['Varun', 19], ['Kakunami', 19], ['Vikas', 21]]
result=[]
temp=max(nl, key=lambda x: x[1])
largest, larger = temp[1], temp[1]
for num in nl:
if num[1] < largest:
largest, larger = num[1], largest
elif num[1] < larger:
larger = num[1]
result.append(larger)
print(result)
Answer
Get the min of the total elements, filter using that valid then get min of remaining and keep elements equal to min of remaining:
from operator import itemgetter # min of all elements mn = min(nl, key=itemgetter(1))[1] # remove elements equal to min filtered = [x for x in nl if x[1] != mn] # get min of remaining mn_fil = min(filtered,key=itemgetter(1))[1] # filter remaining out = [x for x in filtered if x[1] == mn_fil] print(out) [['Harsh', 20], ['Beria', 20]]
Works for both your cases:
In [19]: nl = [['Prashant', 32], ['Pallavi', 36], ['Dheeraj', 39], ['Shivam', 40]] In [20]: from operator import itemgetter In [21]: mn = min(nl, key=itemgetter(1))[1] In [22]: filtered = [x for x in nl if x[1] != mn] In [23]: mn_fil = min(filtered,key=itemgetter(1))[1] In [24]: out = [x for x in filtered if x[1] == mn_fil] In [25]: out Out[25]: [['Dheeraj', 36]]
Using a single for loop we remove all elements from the temp list if we find a lower element, if we find and equally lower one we append it:
mn = min(nl, key=itemgetter(1))[1]
temp = []
best = float("inf")
for ele in nl:
if mn < ele[1] < best:
best = ele[1]
temp = []
out.append(ele)
elif ele[1] == best:
temp.append(ele)
print(temp)