Today I am going to explain the concept that I was confused with at the beginning(While learning python).
Well, the topic is list slicing.To me, this notation needs a bit of picking up. It looks extremely powerful,
but I haven't quite got my head round it and am looking for a good guide.This post will be a simple short explaination of this
Generally, List slicing can be easily understood except for negative index accessing.So, let me explain this concept by naming the indices as
start and end and the skipping number as step.My explaination will be similar to the implementation of range method in python.
There is also the step value, which can be used with any of the above:
The key point to remember is that the :end value represents the first value that is not in the selected slice.
So, the difference beween end and start is the number of elements selected (if step is 1, the default).
The other feature is that start or end may be a negative number, which means it counts from the end of the array instead of the beginning. So:
Python is kind to the programmer if there are fewer items than you ask for.
For example, if you ask for a[:-2] and a only contains one element, you get an empty list instead of an error.
Sometimes you would prefer the error, so you have to be aware that this may happen.