This is so simple and smart. I love it!

Why doesn't the title function capitalize the second chr?? I don't understand....

Clerver but completely unreadable.

Nice work, but please don't change the function signature.

This will make more upper letters than needed, text='2lame' >>> 2Lame

x = [0, 1, 2, 3] # It's the way python handles slices.
y = x[0:10]      # If you put try to slice to a number higher than len(str), 
# y will be = [0, 1, 2, 3] # It will default to len(str).

I feel like this is just too much for a list comprehension to be well readable.
The solution itself is fine.

From all solution I like this one the most. Clever and simple.

How is it handling empty string?

Yes, you are right!

I benchmarked this solution and your solution with valgrind, found:

total heap usage: 71 allocs, 71 frees, 9,658 bytes allocated
total heap usage: 20 allocs, 20 frees, 5,959 bytes allocated

• both built with cargo build --release
• run generate_shape(50)

resolved

Wow, quite fast :) Thank you!