conditional statements on multiple lists with 1 output-CodePudding

I am starting to learn python for a thesis project and here I am looking to get an output array using a conditional statement taking elements from 3 different arrays and need some guidance on how to approach this:

# I have 3 lists here with readings from a sensor:
summer = [92, 99, 86]
autumn = [91, 98, 82]
winter = [93, 96, 83]

# I want to perform this conditional statements on the arrays 
# using the 1st element of each arrays, then the 2nd element
# and lastly the 3rd elements from each array:

if summer >= 90 and autumn >= 90 and winter >= 90:
    a = 1

elif summer >= 90 and autumn >= 90 and winter >= 70:
    a = 2

elif summer >= 50 and autumn >= 50 and winter >= 50:
    a = 3

else:
    a = 4

So in this example I am looking for a singular overall output of a = [1,1,3]

can anyone help with how I should approach this?

CodePudding user response：

Use a for loop to iterate through the lists:

summer = [92, 99, 86]
autumn = [91, 98, 82]
winter = [93, 96, 83]

out = []

for s, a, w in zip(summer, autumn, winter):
    if s >= 90 and a >= 90 and w >= 90:
        out.append(1)
    elif s >= 90 and a >= 90 and w >= 70:
        out.append(2)
    elif s >= 50 and a >= 50 and w >= 50:
        out.append(3)
    else:
        out.append(4)

print(out) # [1, 1, 3]

CodePudding user response：

You could use indexing to access the contents of each array/list:

summer = [92,99,86]
autumn = [91,98,82]
winter = [93,96,83]

a = []

#range(3) since 3 is the length of each array
for i in range(3): 
   if summer[i]>=90 and autumn[i]>=90 and winter[i]>=90:
       n=1

   elif summer[i]>=90 and autumn[i]>=90 and winter[i]>=70:
       n=2

   elif summer[i]>=50 and autumn[i]>=50 and winter[i]>=50:
       n=3

   else:
       n=4
   
   a.append(n)


print(a)

CodePudding user response：

I prefer a "table driven" approach to this kind of problem rather than encumbering the logic with "magic" numbers. Something like this:

summer = [92, 99, 86]
autumn = [91, 98, 82]
winter = [93, 96, 83]

cv = [(90, 90, 90), (90, 90, 70), (50, 50, 50)]

av = []

for t in zip(summer, autumn, winter):
    for i, c in enumerate(cv, 1):
        if all(m >= n for m, n in zip(t, c)):
            av.append(i)
            break
    else:
        av.append(i 1)

print(av)

Output:

[1, 1, 3]

The advantage of this is that the core functionality doesn't change. You just need to change the lists (summer, autumn, winter & cv) appropriately