Python-变量和字符串

0. 以下哪个变量的命名不正确？为什么？

    (A) MM_520  (B) _MM520_  (C) 520_MM  (D) _520_MM

答：C不对，因为数字不能做开头

1.0>>>myteacher = '小甲鱼'

>>>yourteacher = myteacher

>>>yourteacher = '黑夜'

>>>print(myteacher)

答：小甲鱼

2.0>>> myteacher = '小甲鱼'

>>> yourteacher = myteache

>>> myteacher = '黑夜'

>>> print(yourteacher)

答：小甲鱼

3.0

>>>first = 520

>>>second = '520'

>>>first = second

>>>print(first)

答：520

4.0除了使用反斜杠（\）进行字符转义，还有什么方法可以打印：Let's go! 这个字符串？

答：str = 'Let'+"'"+'s'+' '+'go!'