Cannot sort array into ascending order in Python

Question

I know I could use the sort() function, but I am trying to do this without using that.

from random import randint
# Create variables
numberArray = [0]*20

# Populate array
for i in range(0,20):
    numberArray[i] = randint(0,300)

# Sort array into ascending order
print("Sorting array into ascending order...")

sortedAscending = False
while sortedAscending == False:
    for i in range(0,20):
        sortedAscending = True
        if i != (len(numberArray)-1):
            if numberArray[i] > numberArray[i+1]:
                temp = numberArray[i]
                numberArray[i] = numberArray[i+1]
                numberArray[i+1] = temp
                sortedAscending = False
                for j in range(0,20):
                    print(numberArray[j])
                print("END OF ARRAY")
                print()

for i in range(0,20):
    print(numberArray[i])

It starts sorting the array, but then fails to sort any numbers after a few loops. Please help. Note: the loop with "END OF ARRAY" is for debugging.

(1) Show how it fails, don't just say that it fails. (2) StackOverflow's focus is on practical questions (see stackoverflow.com/help/on-topic); exercises are... not ideal. — Charles Duffy
– Charles Duffy, Commented Sep 5, 2017 at 16:04
Welcome to Stack Overflow! It is difficult to offer solutions when the problem statement is simply, "it doesn't work". Please edit your question to give a more complete description of what you expected to happen and how that differs from the actual results. See How to Ask for hints on what makes a good explanation. — Toby Speight
– Toby Speight, Commented Sep 5, 2017 at 16:05
(This is... a bubble sort, I think? You might edit the title to say you're trying to implement a bubble sort, so people who want to help with practical problems can see that and go elsewhere, rather than clicking through and being annoyed). — Charles Duffy
– Charles Duffy, Commented Sep 5, 2017 at 16:06

chowsai · Accepted Answer · 2017-09-05 16:34:05Z

try this and let me know if it works :) (I've tested it 2-3 times so far it has been working well)

from random import randint
# Create variables
numberArray = [0]*20

# Populate array
for i in range(0,20):
    numberArray[i] = randint(0,300)
# Sort array into ascending order
print("Sorting array into ascending order...")

sortedAscending = False
while sortedAscending == False:
    sortedAscending = True # this should be before the for loop
    for i in range(0,20):
        if i != (len(numberArray)-1):
            if numberArray[i] > numberArray[i+1]:
                temp = numberArray[i]
                numberArray[i] = numberArray[i+1]
                numberArray[i+1] = temp
                sortedAscending = False
                for j in range(0,20):
                    print(numberArray[j])
                print("END OF ARRAY")
                print()

for i in range(0,20):
    print(numberArray[i])

I moved the sortedAscending = True out of the for loop

nagendra547 · Accepted Answer · 2017-09-05 16:39:16Z

You have implemented bubble sort.

In python swapping the values are pretty simple. Suppose you want to swap the values of numberArray[i] and numberArray[i+1] then simply you can use this.

numberArray[i], numberArray[i+1] = numberArray[i+1], numberArray[i]

Here is your code. This code should work fine for you.

from random import randint
# Create variables
numberArray = [0]*20

# Populate array
for i in range(0,20):
    numberArray[i] = randint(0,300)
# Sort array into ascending order
print("Sorting array into ascending order...")

sortedAscending = False
while sortedAscending == False:
    sortedAscending = True # this should be before the for loop
    for i in range(0,20):
        if i != (len(numberArray)-1):
            if numberArray[i] > numberArray[i+1]:
                 numberArray[i], numberArray[i+1] = numberArray[i+1], numberArray[i]
                 sortedAscending = False
for i in range(0,20):
    print(numberArray[i])

Collectives™ on Stack Overflow

Cannot sort array into ascending order in Python

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related