三种状态，哪种能提交

can_commit 判断当前能不能完成这次合并提交：文件里还有标记 → 不行；标记删干净但没 add → 也不行；删干净且 add 了 → 可以。运行下面这段程序：

def is_marker(line):
    return line.startswith(("<<<<<<<", "=======", ">>>>>>>"))

def can_commit(text_lines, staged):
    if any(is_marker(l) for l in text_lines):
        return False
    return staged

dirty = ["<<<<<<< ours", "PORT = 8080", "=======",
         "PORT = 9000", ">>>>>>> theirs"]
clean = ["PORT = 9000"]
print(str(can_commit(dirty, False)) + "/" +
      str(can_commit(clean, False)) + "/" +
      str(can_commit(clean, True)))