DELETION OPERATION

python provides operator for deleting/removing an item from a list. There are many methods for deletion:

if index is known,you can use pop[ ] or del
if the element is known,not the index,remove[ ]can be used.
to remove more then one element,del[ ]with list slice can be used.

POP( ):

The pop() method removes and returns last object or obj from the list.

Syntax

Following is the syntax for pop() method −

list.pop(obj = list[-1])

Parameters

obj − This is an optional parameter, index of the object to be removed from the list.

Return Value

This method returns the removed object from the list.

Example

The following example shows the usage of pop() method.

list 1 = ['physics', 'Biology', 'chemistry', 'maths']

list 1.pop()

print ("list now : ", list 1)

list 1.pop(1)

print ("list now : ", list 1)

output:

  list now :  ['physics', 'Biology', 'chemistry']

  list now :  ['physics', 'chemistry']

DEL STATEMENT

The del statement can be used to remove an item from a list by referring to its index, rather than its value. For example, if you have a list with five values, like this:

a = [1, 2, 3, 4, 5]

and you want to remove the second listed value (2), you can use del to do so. The second listed value has an index of 1, so to remove the value, the del syntax would need to look like this:

del a[1]

Now a will look like this:

a = [1, 3, 4, 5]

REMOVE( )

remove() is an inbuilt function in Python programming language that removes a given object from the list. It does not return any value.

Syntax:

list_name.remove(obj)

Parameters:

obj - object to be removed from the list

Returns:

 The method does not return any value

but removes the given object from the list.

Note:It removes the first occurrence of the object from the list.

Example:

# Python 3 program to demonstrate the use of

# remove() method

# the first occurrence of 1 is removed from the list

list 1 = [ 1, 2, 1, 1, 4, 5 ]

list 1.remove(1)

print(list 1)

# removes 'a' from list 2

list 2 = [ 'a', 'b', 'c', 'd' ]

list 2.remove('a')

print(list 2)

output:

  [2, 1, 1, 4, 5]

  ['b', 'c', 'd']

MAX( )

Python list method max returns the elements from the list with maximum value.

Syntax

Following is the syntax for max() method −

max(list)

Parameters

list − This is a list from which max valued element to be returned.

Return Value

This method returns the elements from the list with maximum value.

Example:

list 1, list 2 = [123, 'xyz', 'zara', 'abc'], [456, 700, 200]

print "Max value element : ", max(list 1)

print "Max value element : ", max(list 2)

output:

  Max value element :  zara

  Max value element :  700

MIN( )

Python list method min() returns the elements from the list with minimum value.

Syntax

Following is the syntax for min() method −

min(list)

Parameters

list − This is a list from which min valued element to be returned.

Return Value

This method returns the elements from the list with minimum value.

Example:

list 1, list 2 = [123, 'xyz', 'zara', 'abc'], [456, 700, 200]

print "min value element : ", min(list 1)

print "min value element : ", min(list 2)

output:

  min value element :  123

  min value element :  200

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