How to sort list of strings without using any pre-defined function? - python-3.x

Question

I am new to python and I am stuck to find solution for one problem.
I have a list like ['hello', 'world', 'and', 'practice', 'makes', 'perfect', 'again'] which I want to sort without using any pre defined function.
I thought a lot but not able to solve it properly.
Is there any short and elegant way to sort such list of string without using pre-defined functions.
Which algorithm will be best suitable to sort list of strings?
Thanks.

Answer 1

This sounds like you're learning about sorting algorithms. One of the simplest sorting methods is bubblesort. Basically, it's just making passes through the list and looking at each neighboring pair of values. If they're not in the right order, we swap them. Then we keep making passes through the list until there are no more swaps to make, then we're done. This is not the most efficient sort, but it is very simple to code and understand:
values = ['hello', 'world', 'and', 'practice', 'makes', 'perfect', 'again']
def bubblesort(values):
'''Sort a list of values using bubblesort.'''
sorted = False
while not sorted:
sorted = True
# take a pass through every pair of values in the list
for index in range(0, len(values)-1):
if values[index] > values[index+1]:
# if the left value is greater than the right value, swap them
values[index], values[index+1] = values[index+1], values[index]
# also, this means the list was NOT fully sorted during this pass
sorted = False
print(f'Original: {values}')
bubblesort(values)
print(f'Sorted: {values}')
## OUTPUT ##
# Original: ['hello', 'world', 'and', 'practice', 'makes', 'perfect', 'again']
# Sorted: ['again', 'and', 'hello', 'makes', 'perfect', 'practice', 'world']
There are lots more sorting algorithms to learn about, and they each have different strengths and weaknesses - some are faster than others, some take up more memory, etc. It's fascinating stuff and worth it to learn more about Computer Science topics. But if you're a developer working on a project, unless you have very specific needs, you should probably just use the built-in Python sorting algorithms and move on:
values = ['hello', 'world', 'and', 'practice', 'makes', 'perfect', 'again']
print(f'Original: {values}')
values.sort()
print(f'Sorted: {values}')
## OUTPUT ##
# Original: ['hello', 'world', 'and', 'practice', 'makes', 'perfect', 'again']
# Sorted: ['again', 'and', 'hello', 'makes', 'perfect', 'practice', 'world']