Lists act as a basic data structure in Python. A list can be defined as a mutable, ordered sequence of elements. The elements inside the list are also addressed as items in general. In Python, the items in the list are defined within quotes of  square brackets. Lists pose a greater advantage to the developer when large samples of a similar kind are addressed in the program. Lists allow the user to reduce the size of the code and also apply a single operation on all the elements inside the list in one line.
It is important to note that individual characters inside a string cannot be manipulated, for example
print(x) # results in ERROR
x = y # results in ERROR
But a list provides an oppurtunity to edit its elements. 'string' can be converted into ['s', 't', 'r', 'i', 'n', 'g'] and then above operations can be applied on it. Hence list can be defined as mutable set of elements. To understand better let us consider a list with few strings,
Success = [ 'hard_work', 'dedication' , 'punctual', 'discipline']
[ 'hard_work', 'dedication' , 'punctual', 'discipline']
Indexing the elements
The index of elements starts from 0 and goes up to 'n' incrementing one for n+1 elements.
- print(Success) # returns punctual
- print(Success) # returns "IndexError: list index out of range" since that index is not available in defined list.
- We can also use negetive index which counts from -n to the first element to -1 for the last element.
- print(Success[-2]) # returns puctual
- print('you need to have_' + Success[-3] + '_to be successful') # returns "you need to have_dedication_to be succesful
Adding new elements to the list
Success = 'hygenic' # adding the element in the index we want to pushing other elements eventually to the next index.[ 'hard_work', 'hygenic', 'dedication' , 'punctual', 'discipline']
By append() method
Success.append('workout') # can also be added as Success.insert(4,'workout') to insert workout in 4th position
[ 'hard_work', 'hygenic', 'dedication' , 'punctual', 'discipline', 'workout']
Deleting an element from the list
del Success # hygenic deleted # pop command can also be used to delete elements from a list at a specified index.
[ 'hard_work', 'dedication' , 'punctual', 'discipline', 'workout']
Printing only a section of elements in a list
consider a list of elements
a = ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10']
Now, to access only the first 4 elements we write as:
Output: ['1', '2', '3', '4']
To print elements in steps of 2. Or to print all odd numbers in the above list we can write the Python code as:
print(a[0:9:2]) # from 0th index to 9th index at steps of 2.
Output: ['1', '3', '5', '7', '9']
or if the elements are addressed from 0th ['1', '3', '5', '7', '9']