Algorithm to find 100 closest stars to the origin

Question

First let me phrase the proper question:

Q: There is a file containing more than a million points (x,y) each of which represents a star. There is a planet earth

Answer 1

import sys,os,csv

iFile=open('./file_copd.out','rU')
earth = [0,0]



##getDistance return distance given two stars
def getDistance(star1,star2):
    return sqrt((star1[0]-star2[0])**2 +(star1[1]-star2[1])**2 )


##diction dict_galaxy looks like this  {key,distance}  key is the seq assign to each star, value is a list [distance,its cordinance]
##{1,[distance1,[x,y]];2,[distance2,[x,y]]}
dict_galaxy={}
#list_galaxy=[]
count = 0
sour=iFile.readlines()
for line in sour:
    star=line.split(',')   ##Star is a list [x,y]
    dict_galaxy[count]=[getDistance(earth,star),star]
    count++

###Now sort this dictionary based on their distance, and return you a list of keys.
list_sorted_key = sorted(dict_galaxy,key=lambda x:dict_galaxy[x][0])

print 'is this what you want %s'%(list_sorted_key[:100].to_s)
iFile.close()