Python 我想反转以下代码输出的格式(行和行号都应该是相反的顺序)
输出:Python 我想反转以下代码输出的格式(行和行号都应该是相反的顺序),python,Python,输出: def ls(): with open("todo.txt",'r+') as file: lines = file.readlines() # lines = reversed(lines) for num,line in enumerate(lines): print(num,line) 预期产出: 0 Lemon 1 StarFruit 2 Banana
def ls():
with open("todo.txt",'r+') as file:
lines = file.readlines()
# lines = reversed(lines)
for num,line in enumerate(lines):
print(num,line)
预期产出:
0 Lemon
1 StarFruit
2 Banana
3 Apple
4 Grapes
使用reversed()向后逐行读取文件
将呼叫放回
已反转的。这是正确的。然后更改最后一行以实际打印所需的数字:print(len(lines)-num,line)
。它会产生TypeError:。list\u reverseiterrator
类型的对象没有len()啊,对不起,是Python 2遗留的习惯。使用len(列出(行))
。我还需要行号(降序)
5 Grapes
4 Apple
3 Banana
2 Starfruit
1 Lemon
textfile = open("todo.txt")
lines = textfile.readlines()
for line in reversed(lines):
print(line)