Simple sort function

Question

I am learning Python and for practice I have written this function which sorts a list.

Can you please provide feedback on how I have structured it and what better ways could be there to write it for optimization/structuring?

originallist=[5, 4, 0, 3, 2,1] lowervalue=int() duplicatelist=originallist[:] ## This list is used to compare each element of the list with the first index of original list sortedlist=[] ## Sorted list while len(originallist)>0: # See if there are any elements left in list original list lowervalue=0.01 for i in duplicatelist: if originallist[0]<=i: temp=originallist[0] print('Temp: ', temp) elif originallist[0]>i: temp=i print('Temp: ', temp) if lowervalue>temp or lowervalue==0.01: lowervalue=temp print('LowerValue: ', lowervalue) sortedlist.append(lowervalue) print('Sorted List: ', sortedlist) duplicatelist.remove(lowervalue) print('Duplicate List: ', duplicatelist) originallist.remove(lowervalue) print('original List: ', originallist, ' \n') print(f'Sorted List :' , sortedlist) 

Thank you!

Answer 1

There's some odd features to this code, even for a coding practice exercise. Python of course has a couple of list sorting techniques which you should absolutely use in normal circumstances.

So accepting that you are doing this for practice, I wonder what the point of the duplicatelist is? Or indeed temp? Are these development fossils of some earlier process that you have modified? Looping across this list just seems to find the minimum value in the remaining original list anyway, so

originallist=[5, 4, 8, 2, 3, 6, 0, 1, 7] sortedlist=[] ## Sorted list while len(originallist)>0: # See if there are any elements left in original list lowervalue = originallist[0] for i in originallist: if lowervalue > i: lowervalue = i print('New LowerValue: ', lowervalue) sortedlist.append(lowervalue) print('Growing Sorted List: ', sortedlist) originallist.remove(lowervalue) print('Reduced Original List: ', originallist, ' \n') print('Sorted List :' , sortedlist) 

would apparently do the same.

Of course there is also a min function that would find lowervalue quickly. This eliminates the inner loop (is this maybe why you didn't use it?):

originallist = [5, 4, 8, 2, 3, 6, 0, 1, 7] sortedlist=[] ## Sorted list while len(originallist)>0: # See if there are any elements left in original list lowervalue = min(originallist) print('LowerValue: ', lowervalue) sortedlist.append(lowervalue) print('Growing Sorted List: ', sortedlist) originallist.remove(lowervalue) print('Reduced Original List: ', originallist, ' \n') print('Sorted List :' , sortedlist) 

Using remove from a list can be slow - effectively rewriting the remainder of the list. For the purposes you have here, I don't think it makes an appreciable difference and has the slight advantage of being easy to understand.

One construct you will often see in a reducing list is phrasing the while loop like this:

while originallist: 

... any non-empty list evaluates as True in such a test, so this is the same test as you are making.