文件操作

fr =open('plainText.txt',mode='r',encoding='utf-8')
plainText=fr.read()
print('明文：'+plainText)
print('密文：',end='')
fw =open('dearText.txt',mode='a',encoding='utf-8')
for c in plainText:
    print(chr(ord(c)+2),end='')
    fw.write(chr(ord(c)+2))

cars=['Jaguar','Benz','Lamborghini','Bugatti']
cars.append('Maserati')
cars.pop()
print(cars)

cars=['Jaguar','Benz','Lamborghini','Bugatti']
cars.append('Maserati')
print(len(cars))

cars=['Jaguar','Benz','Lamborghini','Bugatti']
cars.append('Maserati')
cars[1]='Jaguar'
print(cars[1])