索引超出范围,文件读取行

我创建了一个列表 h 但是,当我尝试运行代码时,我得到了新文件的内容:

IndexError: list index out of range

这就是我所拥有的,我的代码是否没有创建列表?

def lab6 (fname):
    """writes in new file with text from existing file"""
    f = open('lab6.txt','a+')
    s = open(fname, 'r', encoding = "ISO-8859-1")
    sc = s.readlines() #creates a list with items in s
    f.write(sc[0]) #copy first line
    #skip next 18 lines
    f.write(str(sc[19:28])) #copy next 9 lines to lab6 
    h = f.readlines() #puts contents of lab6 into list
    print(h) #prints that list
    t = h [2] #retrieve 3rd item in list
    print(t.range(0,3)) #print 1st 3 letters of 3rd item in list