### Nested lists

Lists
can
be
included
within

the
main
big
list
as
an
element
of
the
main
list.
These
inner
lists
are
called
"sub-lists"
.
list_name=[item1,[item21,item22,item23],item3,item4]
num_list = [1, 2, [3, 4]]
print(num_list)
1, 2, [3, 4]]

### Indexing in Nested List

If
we
want
an
item
within
the
nested
list
or
sublist
of
the
list,
we
the
index
of
the
item
in
the
sublist
(containing
the
item)
along
with
the
nested
list/sublist
index
number.
list_name[index of sublist containing the item][index of the item in that sublist]
num_list = [1, 2, [3, 4]]
print(num_list[2][0])

list_num = [1, 2, [3, [4, 5]]]
print(list_num[2][1][1])
3
5

### Adding, Replacing or Deleting values by slicing

Nested
lists
can
be

or
changed

within
a
list
by
slicing
with
the
given
indices.
#Adding an element to the list using slicing
list_name[starting_index:starting_index]=[value]
We
can
replace
more
than
one
element
in
one
go.
We
can
also
replace
2
or
more
elements
with
a
lesser
number
of
elements.
list_name[starting_index:ending_index]=[[value1,value2,...]]
Elements
can
also
be
removed
from
a
list
with
the
help
of
slicing.
list_name[starting_index:ending_index]=[]
a = [1, 2, 5, 6]
a[2:2] = [[3, 4]]
#The list [3,4] gets added between the 2nd and 3rd element
print(a)

a = [1, 2, 5, 6]
a[2] = [3, 4]
print(a)

a = [1, 2, 3, 4, 5]
a[1:3] = ['a','b']
print(a)

a = [1, 2, 3, 4, 5]
a[1:3] = ['a']
print(a)

a = [1, 2, 3, 4, 5]
a[1:3] = []
print(a)
[1, 2, [3, 4], 5, 6]
[1, 2, [3,4], 6]
[1, 'a', 'b', 4, 5]
[1, 'a', 4, 5]
[1, 4, 5]