如何在二维列表的一行中找到最大值及其索引？

Question

I have a 2D list. I want to find the max value and its index of each row. Here is the list

q_table = [[0.16,  0.40,  0.61,  0.48,  0.20],
           [0.42,  0.79,  0.64,  0.54,  0.52],
           [0.64,  0.64,  0.24,  0.93,  0.43],
           [0.33,  0.54,  0.61,  0.43,  0.29],
           [0.25,  0.56,  0.42,  0.69,  0.62]]

Output:

0.61 2
0.79 1
0.93 3
0.61 2
0.69 3

# I'm using python 3.8

Thank You in Advance

Answer 1

as suggested in comments you can use max to get the max values from your list and argmax for getting the position.

np.argmax(q_table, axis=1) #returns list of position of max value in each list.

np.max(q_table, axis=1)  # return list of max value in each  list.

you can then use zip function to iterate both the list together and store the output in list of list

import numpy as np
max_list_with_position=[ [x,y] for x,y in zip(np.argmax(q_table, axis=1),np.max(q_table, axis=1))]
print(max_list_with_position)

output:

[[2, 0.61], [1, 0.79], [3, 0.93], [2, 0.61], [3, 0.69]]

Answer 2

q_table = [[0.16,  0.40,  0.61,  0.48,  0.20],
           [0.42,  0.79,  0.64,  0.54,  0.52],
           [0.64,  0.64,  0.24,  0.93,  0.43],
           [0.33,  0.54,  0.61,  0.43,  0.29],
           [0.25,  0.56,  0.42,  0.69,  0.62]]

rows_count = len(q_table) # to count number of rows
for i in range(rows_count):
    a_row = q_table[i] # taking each row in a variable
    max_value = max(a_row) # find mad value in a single row
    index = a_row.index(max_value) # find the max value's index of a single row
    print("The max value ",max_value, " and Index in ",index)

If there is a better way do suggest.

and here is the output,

The max value  0.61  and Index in  2
The max value  0.79  and Index in  1
The max value  0.93  and Index in  3
The max value  0.61  and Index in  2
The max value  0.69  and Index in  3