What is the difference between Python s list methods append and extend

Question

What's the difference between the list methods append() and extend()?

Answer 1

Python's list methods append and extend add items to the list but the difference is that
we use append when a single item is to be added in the list
while we use extend when more than one item is to be added.

For Example:

Items = [23,34,56]  #create a list
Items

Output

[23, 34, 56]

Items.append([10,40])  #append one element
Items

Output

[23, 34, 56, [10, 40]]

Python will give an error if we try to append more than one item

Items.append(1,2,3)
Items

Output

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-15-e5c36eb74f1f> in <module>
----> 1 Items.append(1,2,3)
      2 Items

TypeError: append() takes exactly one argument (3 given)

While in case of Extend more than one item can be added, extend will extend the list without nesting the list, unlike append. 
For Example:

Items = [23,34,56]
Items

Output

[23, 34, 56]

Items.extend([10,20,30])
Items

Output

[23, 34, 56, 10, 20, 30]

Hope this helps!