1、字符串类型的变量内容有换行的时候，可以用三个单引号或者三个双引号括起来

str='''
I am a student.
Nice to meet you!
'''

print(str)

str="""
I am a student.
Nice to meet you!
"""
print(str)

 2、对字符串中的字符提取时通过索引进行提取，有两种方式

• 从前往后索引，下标从0开始
• 从后往前索引，下标从-1开始

 3、常用的字符串方法

 

 1 star = " NEPTUNE "
 2 #长度为9
 3 print(len(star))
 4 #长度为7
 5 print(len(star.strip()))
 6 
 7 say_hi = "Hello World!"
 8 #输出Hello Kitty!
 9 print(say_hi.replace("World", "Kitty"))
10 
11 say_hi = "Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune,Pluto"
12 #变成了字符串数组['Mercury', 'Venus', 'Earth', 'Mars', 'Jupiter', 'Saturn', 'Uranus', 'Neptune', 'Pluto']
13 arr=say_hi.split(",")
14 print(arr)
15 
16 book_name = "Men Are from Mars, Women Are from Venus"
17 #True
18 is_exist = "Mars" in book_name
19 #False
20 is_exist = "Mars" not in book_name

字符串常用方法

 4、在字符串中引用变量的值

1 name = 'Earth'
2 age = 4.543E9
3 #输出结果为：My name is Earth, 4543000000.0 years old
4 print(f"My name is {name}, {age} years old")