Improve efficiency in Python matching

gistfile1.txt

import os

App=["1"]

for a in App:
    outname="App_"+a+"_target_overlap.csv"
    out=open(outname,'w')
    ticker=0
    cell_comp_id=[]
    final_comp_id=[]

    # make compound with cell activity (to a target) list first

    filename="App_"+a+"_target_Detail_average.csv"
    if os.path.exists(filename):
        file = open (filename)
        line=file.readlines()
        if(ticker==0): # Deal with the title
            out.write(line[0])
            ticker=ticker+1

            for c in line[1:]:
                c=c.split(',')
                if(c[17]==" Cell "):
                     cell_comp_id.append(c[3])
    else:
        cell_comp_id=list(set(cell_comp_id))

# while we have list of compounds with cell activity, now we search the Bio and Enz and make one final compound list

    if os.path.exists(filename):

        for c in line[1:]:
            temporary_line=c #for output_temp
            c=c.split(',')
            for comp in cell_comp_id:
                if (c[3]==comp and c[17]==" Biochemical "):
                    final_comp_id.append(comp)
                    out.write(str(temporary_line))
                elif (c[3]==comp and c[17]==" Enzyme "):
                    final_comp_id.append(comp)
                    out.write(str(temporary_line))
    else:
        final_comp_id=list(set(final_comp_id))

# After we obatin a final compound list in target a , we go through all the csv again for output the cell data

    filename="App_"+a+"_target_Detail_average.csv"

    if os.path.exists(filename):

        for c in line[1:]:
            temporary_line=c #for output_temp
            c=c.split(',')
            for final in final_comp_id:
                if (c[3]==final and c[17]==" Cell "):
                    out.write(str(temporary_line))

    out.close()