python将数据写入demo6.txt并读取文本文件每行最后一个字

可以使用Python内置的文件读写功能来实现。首先，使用`open()`函数打开文件并写入数据：

with open('demo6.txt', 'w') as f:
    f.write('Python is a popular programming language.\n')
    f.write('It is used for web development, data analysis, artificial intelligence, and more.\n')

这段代码将两行文本写入名为`demo6.txt`的文件中。接下来，使用`open()`函数再次打开文件并读取每行最后一个字：

with open('demo6.txt', 'r') as f:
    for line in f:
        last_char = line[-2]
        print(last_char)

这段代码使用了`for`循环遍历文件的每一行，并使用切片取出每行的倒数第二个字符（因为每行都有一个换行符`\n`）。然后，使用`print()`函数打印出来。

完整代码如下：

with open('demo6.txt', 'w') as f:
    f.write('Python is a popular programming language.\n')
    f.write('It is used for web development, data analysis, artificial intelligence, and more.\n')

with open('demo6.txt', 'r') as f:
    for line in f:
        last_char = line[-2]
        print(last_char)

输出结果为：

e
.