My while loop runs infinite times when I think its not supposed to-CodePudding

I was trying write a code that gives index of a minimum value of list one after other For example:

if list=[2,4,1,2,5]
         0 1 2 3 4

output:

[2,0,3,1,4]--> where each element in this corresponds to index of list variable

import math
list=[2,4,1,2,5]
a=[]
i=0
while(i <= (len(list)-1)):
    if(list[i]==min(list)):
        a.append(i)
        list[i]=math.inf
        i=-1
    i =1

print(a)

CodePudding user response：

The problem is that, when list becomes all inf, list[i]==min(list) is true because both list[i] and min(list) are inf. Then i resets to zero and you're in an infinite loop.

print(list, i, list[i], min(list), a)

Outputs:

[inf, inf, inf, inf, inf] 0 inf inf [2, 0, 3, 1, 4, 0, 0, 0, 0]

You can see that list a is being appended with zeroes.

"List" is actually a keyword in Python. Yes, it lets you use it, but that's bad form and you should use something like "lyst" or just "x" or something like that.

CodePudding user response：

Don't use 'list' to define your list. Use something else like 'my_list'.

you can use numpy library to generate an index of a minimum value of a list.

import numpy as np 

my_list = [2,4,1,2,5]
minimum_value_index = [np.argsort(my_list)[x] for x in range(len(my_list))]

print(minimum_value_index)

This will output as following:

[2, 0, 3, 1, 4]

Hope this helps.