i understand that the code given below will not be compltely understood unless i explain my whole of previous and next lines of code. But this is part of the code which is causing so much of delay in my project and want to optimize this. i want to know which code part is faulty and how could this be replaced. i guess,few can say that use of this function is heavy compared and other ligher method are available to do this work

please help,

thanks in advance

for i in range(len(lists)):
    save=database_index[lists[i]]
    #print save
    #if save[1]!='text0194'and save[1]!='text0526':
    using_data[save[0]]=save
    p=os.path.join("c:/begpython/wavnk/",str(str(str(save[1]).replace('phone','text'))+'.pm'))
    x1=open(p , 'r')
    x2=open(p ,'r')
    for i in range(6):
        x1.readline()
        x2.readline()
    gen = (float(line.partition(' ')[0]) for line in x1)
    r= min(enumerate(gen), key=lambda x: abs(x[1] - float(save[4])))
    #print r[0]
    a1=linecache.getline(str(str(p).replace('.pm','.mcep')), (r[0]+1))
    #print a1
    p1=str(str(a1).rstrip('\n')).split(' ')
    #print p1
    join_cost_index_end[save[0]]=p1
    #print join_cost_index_end

    gen = (float(line.partition(' ')[0]) for line in x2)
    r= min(enumerate(gen), key=lambda x: abs(x[1] - float(save[3])))
    #print r[0]
    a2=linecache.getline(str(str(p).replace('.pm','.mcep')), (r[0]+1))
    #print a2
    p2=str(str(a2).rstrip('\n')).split(' ')
    #print p2
    join_cost_index_strt[save[0]]=p2
    #print join_cost_index_strt
    j=j+1

    #print j
    #print join_cost_index_end
    #print join_cost_index_strt
    enter code here

here my database_index has about 2,50,000 entries`