CBSE Class 11 Python List

# CBSE Class 11: Python List 4

How to slice lists in Python?

We can access a range of items in a list by using the slicing operator (colon).

print(n1[1:3])

#counting starts from 0

#will display elements from start to position -1

Example:

n1=[‘c’ , ‘o’ , ‘m’ , ‘p’ , ‘u’ , ‘t’ , ‘e’ , ‘r’]

 0 1 2 3 4 5 6 7 c o m P u t e R

n1=[‘c’,’o’,’m’,’p’,’u’,’t’,’e’,’r’]

print(n1)
output: [‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]

print(n1[1:3])
output: [‘o’, ‘m’]
print(n1[1:4])
output : [‘o’, ‘m’, ‘p’]
print(n1[1:5])
output: [‘o’, ‘m’, ‘p’, ‘u’]
print(n1[2:3])
output: [‘m’]
print(n1[2:4])
output: [‘m’, ‘p’]
print(n1[2:5])
output: [‘m’, ‘p’, ‘u’]

```n1=['c','o','m','p','u','t','e','r']
print(n1)
print(n1[1:3])
print(n1[1:4])
print(n1[1:5])
print(n1[2:3])
print(n1[2:4])
print(n1[2:5])
```

Output:

[‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]
[‘o’, ‘m’]
[‘o’, ‘m’, ‘p’]
[‘o’, ‘m’, ‘p’, ‘u’]
[‘m’]
[‘m’, ‘p’]
[‘m’, ‘p’, ‘u’]

Example: 1

Give output:

n2=[‘c’,’a’,’t’,’a’,’l’,’y’,’s’,’t’]

Positive indexing

 0 1 2 3 4 5 6 7 c a t a l y s t -8 -7 -6 -5 -4 -3 -2 -1

Negative indexing

print(n2)

print(n2[:4])

print(n2[1:4])

print(n2[:-4])

print(n2[:6])

print(n2[:-6])

print(n2[1:6])

print(n2[3:6])

print(n2[2:6])

print(n2[:-2])

output:

[‘c’, ‘a’, ‘t’, ‘a’, ‘l’, ‘y’, ‘s’, ‘t’]

[‘c’, ‘a’, ‘t’, ‘a’]

[‘a’, ‘t’, ‘a’]

[‘c’, ‘a’, ‘t’, ‘a’]

[‘c’, ‘a’, ‘t’, ‘a’, ‘l’, ‘y’]

[‘c’, ‘a’]

[‘a’, ‘t’, ‘a’, ‘l’, ‘y’]

[‘a’, ‘l’, ‘y’]

[‘t’, ‘a’, ‘l’, ‘y’]

[‘c’, ‘a’, ‘t’, ‘a’, ‘l’, ‘y’]

```n2=['c','a','t','a','l','y','s','t']
print(n2)
print(n2[:4])
print(n2[1:4])
print(n2[:-4])
print(n2[:6])
print(n2[:-6])
print(n2[1:6])
print(n2[3:6])
print(n2[2:6])
print(n2[:-2])
```

Output:

[‘c’, ‘a’, ‘t’, ‘a’, ‘l’, ‘y’, ‘s’, ‘t’]
[‘c’, ‘a’, ‘t’, ‘a’]
[‘a’, ‘t’, ‘a’]
[‘c’, ‘a’, ‘t’, ‘a’]
[‘c’, ‘a’, ‘t’, ‘a’, ‘l’, ‘y’]
[‘c’, ‘a’]
[‘a’, ‘t’, ‘a’, ‘l’, ‘y’]
[‘a’, ‘l’, ‘y’]
[‘t’, ‘a’, ‘l’, ‘y’]
[‘c’, ‘a’, ‘t’, ‘a’, ‘l’, ‘y’]

Example: Give output

n1=[‘c’ , ‘o’ , ‘m’ , ‘p’ , ‘u’ , ‘t’ , ‘e’ , ‘r’]

print(n1)

print(n1[:])

print(n1[0:])

print(n1[1:])

print(n1[2:])

print(n1[3:])

print(n1[4:])

print(n1[5:])

output:

[‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]

[‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]

[‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]

[‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]

[‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]

[‘p’, ‘u’, ‘t’, ‘e’, ‘r’]

[‘u’, ‘t’, ‘e’, ‘r’]

[‘t’, ‘e’, ‘r’]

```n1=['c' , 'o' , 'm' , 'p' , 'u' , 't' , 'e' , 'r']
print(n1)
print(n1[:])
print(n1[0:])
print(n1[1:])
print(n1[2:])
print(n1[3:])
print(n1[4:])
print(n1[5:])```

Output:

[‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]
[‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]
[‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]
[‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]
[‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]
[‘p’, ‘u’, ‘t’, ‘e’, ‘r’]
[‘u’, ‘t’, ‘e’, ‘r’]
[‘t’, ‘e’, ‘r’]

Example:

my_list = [‘c’ , ‘o’ , ‘m’ , ‘p’ , ‘u’ , ‘t’ , ‘e’ , ‘r’]
print(my_list[2:5])
print(my_list[:-5])
print(my_list[5:])
print(my_list[:])

Output:

[‘m’, ‘p’, ‘u’]
[‘c’, ‘o’, ‘m’]
[‘t’, ‘e’, ‘r’]
# elements beginning to end
[‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]

```my_list = ['c','o','m','p','u','t','e','r']
print(my_list[2:5])
print(my_list[:-5])
print(my_list[5:])
print(my_list[:])```

Output:

[‘m’, ‘p’, ‘u’]
[‘c’, ‘o’, ‘m’]
[‘t’, ‘e’, ‘r’]
[‘c’, ‘o’, ‘m’, ‘p’, ‘u’, ‘t’, ‘e’, ‘r’]

Important Pages