Today, Bian Xiao will share a summary of several usage methods of arrays in Python, which has good reference value and hopes to help everyone. Come and have a look with Bian Xiao.

Initialization of two-dimensional array

matirx_done = [[0 for i in range(0，len(matirx))]for j in range(0，len(matirx[0])]]

It is initialized to an all-zero matrix with the same size as the matrix.

Multi-level sorting of arrays

In the array idea _ collect = [[3, 1, 2], [3, 2, 1], [3, 2, 2], [3, 1, 1]], the second item is arranged first.

idea _ collect . sort(key = lambda x:(x[ 1]，-x[2]))

Where x[ 1] represents the second positive sequence arrangement and -x[2] represents the third reverse sequence arrangement.

The arrangement results are [[3, 1, 2], [3, 1, 1], [3, 2, 2], [3, 2, 1]].

In a class, multiple functions use the same array without passing parameters.

As shown in the example:

Category partition:

def __init__(self):

self.num_complete = []

Define partition (self, quantity, start, end):

self.num _ compelete = num

Def partition_core (itself):

del self . num _ complete[0]

Among them, self. Num _ compete is an array that two functions in a class can call directly at the same time, but it is best to declare this array in def __init__ first.

The above summary of several methods of using arrays in Python is all that Bian Xiao shares with you.