Question

-179.750 71.250 -20.1 -16.1 -19.0 -15.2 -5.1 -0.7 2.9 4.8 0.9 -3.5 -5.3 -19.0
-179.750 68.750 -23.3 -18.8 -22.7 -16.1 -6.0 -0.2 4.0 5.0 0.9 -5.3 -8.8 -22.2
-179.750 68.250 -23.8 -20.1 -24.1 -16.9 -7.0 -0.2 4.1 4.9 0.2 -6.6 -10.0 -22.7
-179.750 67.750 -22.6 -19.6 -23.6 -15.9 -5.8 2.3 7.1 7.3 1.5 -6.6 -9.9 -21.7
-179.750 67.250 -24.4 -22.6 -26.4 -18.2 -7.7 1.8 7.3 6.7 -0.5 -10.1 -13.3 -24.3

(txt file values provided above)

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Hello!! Could someone please help me that, skip using the first column

and each value per row in the second column if greater than 68.500, elif less than 68.250,

please takes the list of lists and an integer column index.

Returns a new list that contains the average values of the target column from all of the rows.

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if list[1] >= 68.500, the lists which would be used are this:

-179.750 71.250 -20.1 -16.1 -19.0 -15.2 -5.1 -0.7 2.9 4.8 0.9 -3.5 -5.3 -19.0
-179.750 68.750 -23.3 -18.8 -22.7 -16.1 -6.0 -0.2 4.0 5.0 0.9 -5.3 -8.8 -22.2

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if list[1] <=68.250, the lists which would be used are this:

-179.750 68.250 -23.8 -20.1 -24.1 -16.9 -7.0 -0.2 4.1 4.9 0.2 -6.6 -10.0 -22.7
-179.750 67.750 -22.6 -19.6 -23.6 -15.9 -5.8 2.3 7.1 7.3 1.5 -6.6 -9.9 -21.7
-179.750 67.250 -24.4 -22.6 -26.4 -18.2 -7.7 1.8 7.3 6.7 -0.5 -10.1 -13.3 -24.3

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both output: [average of column 2, avg of column 3, .... , avg of final column]

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Please do this in python,

Thank you!!!

Answer 1

l=[]
fh = open('values.txt')
while True:
line = fh.readline()
if line!='':
l.append(line.split())
if not line:
break
fh.close()
sum1=[]
sum2=[]
for i in l:
if float(i[1])>=68.500:
sum1.append(i[1::])
elif float(i[1])<=68.250:
sum2.append(i[1::])
sum1 = [[float(j) for j in i] for i in sum1]
sum2 = [[float(j) for j in i] for i in sum2]

avg1=[sum(x) for x in zip(*sum1)]
avg2=[sum(x) for x in zip(*sum2)]

avg1=list(map(lambda x : x/len(sum1),avg1))
avg2=list(map(lambda x : x/len(sum2),avg2))
  
print(avg1)
print(avg2)

It may not be very elegant, strictly sticking to pure python. It's a lot simpler with numpy but since you specified 'list of lists', I stuck to the basics.

Hope it helps let me know if you require further assistance.