Python: map latitude longitude and density

def returnData(fp):
    with open(fp,'r') as f:
        lines = f.read()
    lines = lines.split('\n')
    lines = [line.split(',') for line in lines]
    return lines

def writedensity():
    fp = 'l.txt'
    lines = returnData(fp)
    for line in lines:
        count = 0
        print(line)
        result = getlatlon(line, count)
        if result:
            with open('out','a+') as f:
                f.write(','.join(result+['\n']))

def getlatlon(line, count):
    #from geopy.geocoders import Nominatim as nom
    #g = nom()
    #writedensity()

    try:
        l = g.geocode(line[0])
        lon, lat = l.raw['lon'],l.raw['lat']
        print("found")
        return [lat,lon,line[1]]
    except Exception, e:
        print('.')
        count += 1
        if count > 3:
            return None
        else:
            getlatlon(line, count)
    #from geopy.geocoders import Nominatim as nom
    #g = nom()
    #writedensity()


import matplotlib.pyplot as plt
import numpy as np
from mpl_toolkits.basemap import Basemap
import matplotlib.cm as cm
import math
m = Basemap(resolution='i', projection='cyl', llcrnrlat=0,urcrnrlat=90, llcrnrlon=-180,urcrnrlon=180)
m.drawcoastlines()
m.fillcontinents(color='white',lake_color='gray',zorder=0)
m.drawparallels(np.arange(-80.,81.,20.))
m.drawmeridians(np.arange(-180.,181.,20.))
m.drawmapboundary(fill_color='gray')
m.drawstates()
fp = 'out'
data = returnData(fp)
print(data[1])
print('len_data: ',len(data))
#towns = ["Chicago Illinois", "Minneapolis Minnesota"]
#for name in towns:
lats = []
lons = []
sizes = []
colors = []

for l in data:
    colors.append(int(l[2]))
    #print(l)
#print(max(sizes))
max_size = max(colors)

#print('max_size',max_size,'len sizes',len(sizes))
sizes = []


for line in data:
    lat, lon, size = line[0],line[1],line[2]
    lats.append(lat)
    lons.append(lons)
    cols = (float(size)/float(max_size))#((float(size)/float(max_size)), (0.), (float(size)/float(max_size)))
    #size = (math.log(float(size))+1.)*80.
    size = float(size)*10
    #sizes.append(size)
    #print("read points")
    xpt, ypt = m(lon, lat)
    #print("added points")
    m.scatter(xpt, ypt, s=size, c=cols, marker='o',cmap=cm.jet, alpha=.7)
    #print("added scatters")
plt.show()
print("showing plot")