python - 删除除特定值外的多次出现？

Question

我有一个文本行列表:textlines，它是一个字符串列表(以'\n' 结尾)。

我想删除多次出现的行，不包括那些只包含空格、换行和制表符的行。

换句话说，如果原始列表是:

textlines[0] = "First line\n"
textlines[1] = "Second line \n"
textlines[2] = "   \n"
textlines[3] = "First line\n"
textlines[4] = "   \n"

输出列表为:

textlines[0] = "First line\n"
textlines[1] = "Second line \n"
textlines[2] = "   \n"
textlines[3] = "   \n"

怎么做？

Answer 1

seen = set()
res = []
for line in textlines:
    if line not in seen:
        res.append(line)
        if not line.strip():
            seen.add(line)
textlines = res