下面代码哪里错了,为什么提示"list index out of range"
import reimport randomseq_count = 0list = []list_1 = []list_2 = []seq = []seq_2 = []q = 0v = []count_1 = []with open('sequence.fasta', 'r') as f: for line in f: if line[0] == '>': seq_count += 1 line = 'contig' f = re.sub(r'[N]+|(\n)', '', line) list.append(f) seq = ''.join(list) seq = re.split('contig', seq) seq = seq[1:]print(seq_count)print(seq)while q < 5000: a = random.randint(0, 23) length = len(seq[a]) n = random.randint(0, length-200) seq_5000 = seq[a][n:n + 200] seq_2.append(seq_5000) q += 1# print(seq_2)for line_1 in seq_2: a = line_1.count('G') b = line_1.count('g') c = line_1.count('C') d = line_1.count('c') GC = (a + b + c + d) / 200 list_1.append(GC) list_1.sort(reverse=True)# print(list_1)# print(list_1[0:10])seq_3 = ''.join(seq_2) # //将取出的每一条条200bp的序列转化为字符串list_2.append(seq_3)seq_all = ''.join(list_2) # //将5000条200bp的列表转化为一整条长字符串seq_all_1 = seq_all.upper()# print(seq_all)seq_fen = [seq_all_1[i:i + 4] for i in range(0, len(seq_all_1), 4)]# print(seq_fen)