STD_1.py

def SelectionSort(A):
    '''
    List sorting algorithm that finds smalles element in the list, puts it in the front,
    and repeats the process with the rest of the unsorted elements
    Input: unsorted list
    Output: sorted list with increasing values
    '''
    for i in range(len(A)-1):         #outer loop, goes through all indexes of A list except the last one
        canswap = False               #set flag for nessecity of a swap to False
        minim = i                     #place an index of A list inside minim variable
        for j in range(i+1,len(A)):   #inner loop, goes through indexes of A list starting from current value of outer loop plus one
        if A[j] < A[minim]:           #if  value under current inner loop index is smaller than value under minimum variable index 
            minim = j                 #replace minimum variable with current inner loop value
            canswap = True            #switch flag for necesity of a swap to True
        if canswap == True:           #if flag for necessity of a swap is set to True
        A[i],A[minim] = A[minim],A[i] #swap the minimum value with the current value of the outer loop
    return A                          #return sorted list

print(SelectionSort([4,5,2,8,1]))

#go through all indexes in the list except the last one(as we do not need sorting if there is only one element left). With each iteration indexes of a list which we went trough will be sorted and the rest will be an unsorted part 
# put first unsorted element of the list inside the minimum variable
#search through rest of the unsorted part of the list (without the first element)
#replace current minimum variable with the smaller one that we found
#swap the minimum value with what is in the smallest index of unsorted part of the list