Summary of String Array Reverse Ordering Method in python

How do string arrays in python be arranged in reverse order?Here are a few ways to do this:

1. Array reverse order:

The reverse order of the original elements

(1) Slice

>>> arr = [1,2,3,4,3,4]>>> print (arr[::-1])[4, 3, 4, 3, 2, 1]

(2) reverse()

>>> arr = [1,2,3,4,3,4]>>> arr.reverse()>>> print (arr)[4, 3, 4, 3, 2, 1]

(3) reversed (arr) #Returns an inverted traversable object

arr = [1,2,3,4,3,4]reversed_arr = [] for i in reversed(arr):  reversed_arr.append(i)print (reversed_arr)[4, 3, 4, 3, 2, 1]

2. String inversion:

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(1) String interception

param = 'hello'print (param[::-1])  olleh

(2) Using reversed() to return an invertible iterative object (string implementation)

param = 'hello'rev_str = ''for i in reversed(param):    rev_str += iprint (rev_str)   olleh

(3) Return invertible iterative objects using reversed() (array implementation)

param = 'hello'rev_arr = []for i in reversed(param):  rev_arr.append(i)print (''.join(rev_arr))olleh

Also:

The reverse order after the elements are sorted:

1. sorted(...) generates a new array of arrays

sorted(iterable, cmp=None, key=None, reverse=False) -- > new sorted list

2. arr.sort(...) directly operates on arr, elements within arr are positively ordered

Sorting within elements

param ='hello'#Returns the sort within the element

rev_str =''.join (sorted) (param)] #sorted (param) returns an inverted array ['e','h','l','l','o']print rev_str --- > 'ehllo'