学习笔记(04):600 分钟搞定 Python 入门到实战-字符和字符串-2

立即学习:https://edu.csdn.net/course/play/26676/338775?utm_source=blogtoedu

三、字符串序列切片操作
[参数1:参数2:参数3]，3个参数，参数1，起始字符序列，正数从0开始，从左往右数；负数从-1开始，从左右往左数；参数2，结束字符序列，可正(+)可负(-)，同参数1；参数3，表示步长，可正(+)可负(-)，正数以参数1对应起始字符开始，从左往右数，负数以参数2对应结束字符开始，从右往左数
>>> m = 'python'
>>> n = "book"
>>> r = "python book"
>>> len(r)
11
>>> r[0]
'p'
>>> r[-1]
'k'
>>> r[5]
'n'
>>> r[-6]
'n'
>>> r[1:9]
'ython bo'
>>> r
'python book'
>>> r[1:9:1]
'ython bo'
>>> r[1:9:2]
'yhnb'
>>> r[:9:2]
'pto o'
>>> r[2:]
'thon book'
>>> r[:]
'python book'
>>> r[::-1]
'koob nohtyp'
>>> r[-10:8:2]
'yhnb'
>>> r[8:-10:-2]
'o ot'
>>> r[-4:-10:-2]
'bnh'
>>> r[-4:-10:2]
''
>>>

四、内置函数input()、print()
name.py

#coding：utf-8
"""
your name and age
"""
name = input("your name: ")
age = input("ypur age: ")

after = int(age) + 10

print("your name is: ",name)
print("after ten years, you are ",after)