Earthquake Dot Map

I am trying to make an earthquake dot map on which you could not only figure out its magnitude by the size, but also know its depth by moving your mouse into the circle. It seems that when I was trying to control multiply variable in the same file （e.g. longitude, latitude, magnitude and depth), there’s always wrong with my function and if…else…

import csv
def setup():
    size(800,600)
    f = open("quakes.csv")
    global reader
    reader = csv.reader(f)
    header = reader.next()
    background(255)
    map = loadImage("map.jpg")
    image (map,(width-640)/2,(height-320)/2)
def draw():
    translate(width/2,height/2) 
  
    for row in reader:
        latitude = float(row[0])
        longitude = float(row[1])
        magnitude = float(row[2])
        stroke(155,0,0)
        ellipse(longitude,latitude,magnitude*6,magnitude*6)

A failed version when I trying to add text:

import csv
def setup():
    size(800, 600)
    f = open("quakes.csv")
    reader = csv.reader(f)
    header = reader.next() 
        
    global depths
    depths=[]
    for row in reader:
        depth = float (row[3])
        depths.append(depth)
        
    global latitudes
    latitudes = []
    for row in reader:
        latitude = float (row[0])
        latitudes.append(latitude)
    
    global longtitudes
    longtitudes = [] 
    for row in reader:
        longtitude = float (row[1])
        longtitudes.append(longtitude)
            
def draw():
    background(255)
    depth0 = depths[9]
    depth9=depths[9]
    x=0
    textSize(12)
    text("Depth:",650,460)
    
    for depth in depths:
        for latitude in latitudes:
            for longtitude in longtitudes:
        
                leftEdge = x-longtitude/2
                rightEdge = x+longtitude/2
                upEdge = y+latitude/2
                downEdge = y-latitude/2
    
                if leftEdge < mouseX and mouseX < rightEdge and downEdge < mouseY and mouseY < upEdge:
                    text(depth,670,460)        
                else:
                    text(0,67,460)
                x+=2.5