读取文件，并按原格式输出文件内容的三种方式

filename = 'Car.py'

#读取整个文件
with open(filename) as file_object:
    lines = file_object.read()
    print(lines)


#遍历文件对象
with open(filename) as file_object:
    for line in file_object:
        print(line.strip('\n'))

#将各行存储在一个列表中，再在with代码块外打印它们
with open(filename) as file_object:
    lines = file_object.readlines()

for line in lines:
    print(line.strip('\n'))