How do I find the largest float in a list array?

Question

I'm trying to create a python script for the Huntington-Hill apportionment method. For this, I need the population of each state, the number of seats currently assigned to each state, and value a , where a = p/sqrt(s*(s+1)). I need to identify which state has the largest a value, add one seat to that state and repeat until the state with the smallest population as the largest a . I've created row[3] in my list to store a values but I'm unable to have python identify the largest one.

I've tried to sort row[3] or simply find the max value, but am told 'float' object is not iterable. If I convert it to a string and then sort, it sorts each digit, giving me a list of 9s and then 8s etc.

import math
file_csv = open("statepop2.csv")
data_csv = csv.reader(file_csv)
list_csv = list(data_csv)
for row in list_csv:
    row.append(0)
    row[3] = int(row[1])/math.sqrt(int(row[2])*(int(row[2])+1))
    print(sorted(row[3]))

I'm very new to all this, so any help is much appreciated

Edit: It seems this is a problem with the CSV, not with the sort. I'm not sure what's wrong, nor how to upload my CSV file.

Answer 1

The problem is that row[3] is an integer, not a list. You cannot sort an integer.

I am not sure what you exactly want to do, but try this:

for row in list_csv:
  row.append(0)
  row[3] = int(row[1])/math.sqrt(int(row[2])*(int(row[2])+1))
print(max([row[3] for row in list_csv]))

Answer 2

You are trying to sort the value of a itself, hence giving a float as argument to the sorted() function. It is the same of typing:

sorted(4.3)

As 4.3 is not a list but a float, it is not iterable .

I suggest to simply create a list and appending the value to that list, then printing the sorted list.

import math, csv
file_csv = open("statepop2.csv")
data_csv = csv.reader(file_csv)
list_csv = list(data_csv)
rows = []

for row in list_csv:
    row.append(0)
    row[3] = int(row[1])/math.sqrt(int(row[2])*(int(row[2])+1))
    rows.append(row[3])

print(sorted(rows))

If you need some other data from your CSV (ie the country name?) to be displayed along with the a value, just makes rows a dict :

rows = {}

Then you can add a dict entry, having the other piece of info as key :

countryName = row[x]
rows[countryName] = row[3]

Answer 3

Simply use max() .

a = [1.2, 3.8, 4.9]
b = max(a)

print(b)
# 4.9