date: 2022-05-30 05:45:40

通过jupyter notebook来执行hexo g/d

!cd /blog/ &&./g.sh

jpyter安装主题

!pip install --upgrade jupyterthemes

!jt -t oceans16 -f fira -fs 12 -cellw 90% -ofs 10 -dfs 11 -T

反转字符串

切片方式反转

strn = "Hello world!";
s1 = strn[::-1]
print(strn,'\n','*'*10)
print(s1)

Hello world! 
 **********
!dlrow olleH

通过 reversed()+join()方法反转

s2 = reversed(strn)
print(strn,'\n','*'*10)
print(''.join(s2))

Hello world! 
 **********
!dlrow olleH

通过函数实现

def reversed_string(text):
    result = ''
    for char in text:
        result = char +result
    return result
print(strn,'\n','*'*10)
print(reversed_string(strn))

Hello world! 
 **********
!dlrow olleH

使用reduce实现

from functools import reduce

def reversed_string_reduce(text):
    return reduce(lambda a, b: b + a, text)
print(strn,'\n','*'*10)
print(reversed_string_reduce(strn))

Hello world! 
 **********
!dlrow olleH

python内置函数

list_test = ['a1','a2','a','3','a','4']

print(list_test)
print(' '.join(reversed(list_test)))#反转
print(list(enumerate(list_test)))#组合成索引序列
print(sorted(list_test))#排序

['a1', 'a2', 'a', '3', 'a', '4']
4 a 3 a a2 a1
[(0, 'a1'), (1, 'a2'), (2, 'a'), (3, '3'), (4, 'a'), (5, '4')]
['3', '4', 'a', 'a', 'a1', 'a2']