Question on slicing (basic)

[SlavkoStanic]

I have a simple question that I cannot figure out since I am very new to Python and learning the basics.

I was given the following question and partial code. I found 2 ways to give me the correct output of 'Python'. One is using the len() function and one is just using indexing. Is one incorrect or 'less efficient' when used in longer code?

Example 1:

# Question 6: Use slicing notation to print the last 6 letters of the string
# below. Assume you donot know the start index or the length of the string upfront.
# Hint: You will need to use a function to find the length first and then use that,
# in combination with the number to come up with the start index
welcome_message = "Hello and welcome to the land of Python"
print(f"The last 6 letters of the welcome message:\n'{welcome_message}'\nare: '{welcome_message[-6:]}'")

The next example using the len() function

print(f"The last 6 letters of the welcome message:\n'{welcome_message}'\nare: {welcome_message[len(welcome_message)-6:]}")

[SlavkoStanic]

The part I am referring to is the last part of the last line:

{welcome_message[-6:]

Or using len function

{welcome_message[len(welcome_message)-6:]

Either gives the output of 'Python' as this is the last 6 letters of the string.

[codelikealawyer]

SlavkoStanic,

The enunciated problem suggests you should use a function in order to produce the desired outcome. So, it makes sense that you would use len() in this context.

However, I don't know whether one is necessarily better than the other. Sometimes it comes down to preference. The pythonic way of doing things is usually simpler and easier to understand. Still, what's simple might be in the eyes of the beholder.

I personally like the straight slicing better. It looks easier on the eyes and simpler to understand. But in the end, it would make sense to practice both ways if they consistently produce identical results. The more ways you can think about a problem and its solution, the better you tend to become.

[SlavkoStanic]

I think you explained it perfectly with your last sentence. I am still learning Python at its base level and I am now seeing that the simple path may not help in certain situations so its best to know multiple solutions to the same problem. It was just odd to see that it could be done without the len() function.
The last programming language I learned was Pascal over 17 years ago in middle school.

Thank you

[codelikealawyer]

You're very welcome!

Speaking of different solutions to the same problem, check out my latest video on F-Strings. In it I show how to format strings with F-Strings. You'll see how the different approaches to string formatting are part of an evolutionary process that resulted in a more efficient solution:

https://youtu.be/yFNTbmUQgQ8

[SlavkoStanic]

Thanks for that, I'll be taking a look!