python how to remove spacific line in file

I'm trying to delete from a file.

This is what I am trying to do.

1.importing Easygui

2.Put three modes plus quitting

3. 3 modes are (see, add, delete)

Everything is working except deleting part. this is what I have

    import easygui

    filea = open('GroceryList.txt', 'a')
    fr = open('GroceryList.txt', 'r')
    filer = open('GroceryList.txt', 'r')

    runinng = True
    while runinng:
      a = easygui.choicebox('Do you want to add, delete, or see your list?',
                    choices = ['add', 'delete', 'see', 'quit'])
     if a == 'add':
       ad = easygui.enterbox('What do you want to add')
       filea.write(ad)
       filea.write('\n')
    filea.close()
    filea = open('GroceryList.txt', 'a')


    elif a == 'delete':
       rn = easygui.enterbox('What are you going to delete?')
       rl = fr.readlines()
       for lines in fr:
         if rn in lines:
           line.split()
         fr.close()
         fr = open('GroceryList.txt', 'r')


   elif a == 'see':
     s = filer.readlines()
     easygui.msgbox(s)
   filer.close()
   filer = open('GroceryList.txt', 'r')

   elif a == 'quit':
    runinng = False
  filea.close()
  fr.close()
  filer.close()

The part that is not working is:

    elif a == 'delete':
rn = easygui.enterbox('What are you going to delete?')
rl = fr.readlines()
if rn in fr:
  line.remove()
fr.close()
fr = open('GroceryList.txt', 'r')

As others mentioned in the comments just providing a small script to clear out the doubts you may still have

fr = open('GroceryList.txt', 'r')
rl = fr.readlines()
new_list_to_keep_rows=[]
for row in rl:
    #add rows to keep
    new_list_to_keep_rows.append(row) 

new_file = open('GroceryList_new.txt', 'w')# open file in write mode
for item in new_list_to_keep_rows:
    new_file.write("%s\n" % item)

rename the file when you are sure you have everything.