Exercise - Processing CSV files using a dictionary of lists

import os
import urllib.request as url

url1 = 'https://gist.githubusercontent.com/aakashns/257f6e6c8719c17d0e498ea287d1a386/raw/7def9ef4234ddf0bc82f855ad67dac8b971852ef/loans1.txt'
url2 = 'https://gist.githubusercontent.com/aakashns/257f6e6c8719c17d0e498ea287d1a386/raw/7def9ef4234ddf0bc82f855ad67dac8b971852ef/loans2.txt'
url3 = 'https://gist.githubusercontent.com/aakashns/257f6e6c8719c17d0e498ea287d1a386/raw/7def9ef4234ddf0bc82f855ad67dac8b971852ef/loans3.txt'

url.urlretrieve(url1,'./loans/loans1.txt')
url.urlretrieve(url2,'./loans/loans2.txt')
url.urlretrieve(url3,'./loans/loans3.txt')

def read_csv(path):
    
    #reading the file
    with open(path) as f:
        file_content=f.readlines()
        
    #extracting the header
    headers=file_content[0].strip().split(',')
    
    #converting rest of the file into list of list of loans [[1st loan],[2 loan],....]
    item_list=[]
    for line in file_content[1:]:
        line=line.strip().split(',')  #reading file line-by-line
        
        loans=[]
        for item in line:    #iterating over details of single loan
            if item=='':
                item=0.0
            loans.append(float(item))  #making list of details 
        item_list.append(loans)    #appending to the final loans sheet
        
        
    loan_dict={}
    k=0
    for header in headers:
        item=[]
        for j in range(len(item_list)):   #iterating through all loans
            item.append(item_list[j][k])   #taking single column items and appending
        loan_dict[header]=item
        k+=1
    return loan_dict