Python 如何在文本文件中的单词前添加数字？

我在文本文件中有此菜单：

#菜单1文件
水母怡生梨
鱼汤海鲜干
清蒸海水石斑鱼

我有这个密码：

menuList = input('enter number:')
def printPackage(menuList):
    if menuList == '1':
        with open('menu/Menu1.txt')as f:
            data = f.read()
            print(data)
printPackage(menuList)

我应该向我的代码中添加什么，以便我可以像这样打印文本文件

---------
菜单列表
---------
1水母怡生梨
2鱼汤海鲜干
三。清蒸海水石斑鱼

---

请帮忙。

试试这个蟒蛇式的方法（快得多）：

menuList = input('enter number:')
def printPackage(menuList):
    if menuList == '1':
        with open('menu/Menu1.txt')as f:
            lines = []
            for l_i, line in enumerate(f.read().split('\n'), 1):  # Read the file and split it on newline. Enumerate the results returning index (l_i) and the line. Start l_i at 1
                formatted_line = '%s. %s' % (l_i, line)  # Format it with the line number.
                print(formatted_line)
                lines.append(formatted_line) 

            # If you want to save it.
            with open('menu/Menu1_with_numbers.txt', 'w') as o_f:
                o_f.write('\n'.join(lines))  # Join back the lines on newline and write it out to Menu1_with_numbers.txt

甚至更短：

get_input = input('Enter Number: ')
if not get_input == "1":
    exit()
read_lines = [open("result.txt", "a").write("{}. {}{}".format(counts, line.rstrip("\n"), "\n")) for counts, line in enumerate(open('Menu1.txt'), 1)]

只有一行（LOOL）：

if input("Enter Number: ") == "1" : [open("result.txt", "a").write("{}. {}{}".format(counts, line.rstrip("\n"), "\n")) for counts, line in enumerate(open('Menu1.txt'), 1)]

---

迭代文件行并使用

枚举

获取索引。感谢您的帮助和解释。帮助很多如果我只想要文本文件中的特定字行，我应该对程序做什么更改？例1。A 2。文本文件中的B3.C…如何仅获取1。A或1.A和2.C，其中C变为数字2

if input("Enter Number: ") == "1" : [open("result.txt", "a").write("{}. {}{}".format(counts, line.rstrip("\n"), "\n")) for counts, line in enumerate(open('Menu1.txt'), 1)]