This article mainly introduces the 6 methods of python to realize the reverse output of the specified input string, which has certain reference value. Interested friends can refer to it
For a given String, output in reverse order. This task is a very simple operation for Python. After all, the powerful list and string processing functions are enough to cope with these problems. Today I summarized the reverse order output of strings in Python. Several commonly used methods, a total of six methods have been summarized. I personally think it is relatively comprehensive. If you have other methods, please feel free to add them.
Method 1:Use the string slicing function directly Reverse the string
Method 2:Convert the string to a list using the reverse function
Method 3:Create a new list from back to front Add elements
Method 4: Use the ready-made method of collections module extendleft
Method 5: Recursive implementation
Method 6: Use the basic Swap operation to exchange symmetrically positioned characters based on the middle
The following is the specific implementation:
#!usr/bin/env python #encoding:utf-8 ''''''' __Author__:沂水寒城 功能:输入一个字符串,倒叙输出 ''' import collections def func1(one_str): ''''' 直接使用字符串切片功能逆转字符串 ''' return one_str[::-1] def func2(one_str): ''''' 将字符串转换为列表使用reverse函数 ''' one_str_list = list(one_str) one_str_list.reverse() return ''.join(one_str_list) def func3(one_str): ''''' 新建一个列表,从后往前添加元素 ''' one_list=[] for i in range(len(one_str)-1,-1,-1): one_list.append(one_str[i]) return ''.join(one_list) def func4(one_str): ''''' 借助于collections模块现成的方法extendleft ''' deque1=collections.deque(one_str) deque2=collections.deque() for one_char in deque1: deque2.extendleft(one_char) return ''.join(deque2) def func5(one_str): ''''' 递归实现 ''' if len(one_str)<=1: return one_str return one_str[-1]+func5(one_str[:-1]) def func6(one_str): ''''' 借助基本的Swap操作,以中间为基准交换对称位置的字符 ''' one_str_list=list(one_str) if len(one_str_list)==0 or len(one_str_list)==1: return one_str_list i=0 length=len(one_str_list) while i < length/2: one_str_list[i], one_str_list[length-i-1]=one_str_list[length-i-1], one_str_list[i] i+=1 return ''.join(one_str_list) def main_func(str_list): ''''' 主调用函数 ''' for one_str in str_list: one_list=[] one=[] one_list.append(func1(one_str)) one_list.append(func2(one_str)) one_list.append(func3(one_str)) one_list.append(func4(one_str)) one_list.append(func5(one_str)) one_list.append(func6(one_str)) print '字符串{0}逆序为:'.format(one_str) print one_list if __name__ == '__main__': str_list=['123456','abcdefg','zyxvuw','Together_CZ'] main_func(str_list)
The results are as follows:
字符串123456逆序为: ['654321', '654321', '654321', '654321', '654321', '654321'] 字符串abcdefg逆序为: ['gfedcba', 'gfedcba', 'gfedcba', 'gfedcba', 'gfedcba', 'gfedcba'] 字符串zyxvuw逆序为: ['wuvxyz', 'wuvxyz', 'wuvxyz', 'wuvxyz', 'wuvxyz', 'wuvxyz'] 字符串Together_CZ逆序为: ['ZC_rehtegoT', 'ZC_rehtegoT', 'ZC_rehtegoT', 'ZC_rehtegoT', 'ZC_rehtegoT', 'ZC_rehtegoT']
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