List Methods

append() Method

Appends an element at the end of list.

SYNTAX:

list.append(element)

Example:

courseList = ['C', 'Java', 'PHP'] print(courseList) courseList.append('Python') print(courseList)

Output:

['C', 'Java', 'PHP'] ['C', 'Java', 'PHP', 'Python']

clear() Method

Removes all the elements from the list.

SYNTAX:

list.clear()

Example:

courseList = ['C', 'Java', 'PHP'] print(courseList) courseList.clear() print(courseList)

Output:

['C', 'Java', 'PHP'] []

copy() Method

Returns a copy of list.

SYNTAX:

list.copy()

Example:

courseList = ['C', 'Java', 'PHP'] print(courseList) dupList = courseList.copy() print(dupList)

Output:

['C', 'Java', 'PHP'] ['C', 'Java', 'PHP']

count() Method

Returns number that an element occurred in the list.

SYNTAX:

list.count()

Example:

courseList = ['C', 'Java', 'PHP'] print(courseList) print(courseList.count('C'))

Output:

['C', 'Java', 'PHP'] 1

extend() Method

Adds a list of elements or any iterable to the end of current list.

SYNTAX:

list.extend(iterable)

iterable - list, set, tuple, etc.

Example:

courseList = ['C', 'Java', 'PHP'] print(courseList) courseList.extend(['Python', 'Ruby', 'Perl']) print(courseList)

Output:

['C', 'Java', 'PHP'] ['C', 'Java', 'PHP', 'Python', 'Ruby', 'Perl']

index() Method

Returns the position of the first occurrence of an element if found. If the element does not find it raises an exception.

SYNTAX:

list.index(element)

Example1:

courseList = ['C', 'Java', 'PHP'] print(courseList) print(courseList.index('PHP'))

Output1:

['C', 'Java', 'PHP'] 2

Example2:

courseList = ['C', 'Java', 'PHP'] print(courseList) print(courseList.index('Python'))

Output2:

['C', 'Java', 'PHP'] ValueError: 'Python' is not in list

insert() Method

Adds an element into list at specified position.

SYNTAX:

list.insert(position, element)

Example:

courseList = ['C', 'Java', 'PHP'] print(courseList) courseList.insert(2, 'Python') print(courseList)

Output:

['C', 'Java', 'PHP'] ['C', 'Java', 'Python', 'PHP']

pop() Method

Removes an element at specified position.

SYNTAX:

list.pop(position)

Parameter:
position - Optional. A number that specifies the position of the element that you want to be remove. Default value is -1 which means it removes last element.

Example1:

courseList = ['C', 'Java', 'PHP'] print("Before pop():", courseList) print("Popped element:", courseList.pop()) print("After pop():", courseList)

Output1:

Before pop(): ['C', 'Java', 'PHP'] Popped element: PHP After pop(): ['C', 'Java']

Example2:

courseList = ['C', 'Java', 'PHP'] print("Before pop():", courseList) print("Popped element:", courseList.pop(1)) print("After pop():", courseList)

Output2:

Before pop(): ['C', 'Java', 'PHP'] Popped element: Java After pop(): ['C', 'PHP']

remove() Method

Removes the first occurrence of the specified element.

SYNTAX:

list.remove(element)

Example1:

courseList = ['C', 'Java', 'PHP'] print("Before remove():", courseList) courseList.remove('PHP') print("After remove():", courseList)

Output1:

Before remove(): ['C', 'Java', 'PHP'] After remove(): ['C', 'Java']

Example2: If the element not in the list then it raises an exception.

courseList = ['C', 'Java', 'PHP'] print("Before remove():", courseList) courseList.remove('Python') print("After remove():", courseList)

Output2:

Before pop(): ['C', 'Java', 'PHP'] ValueError: 'Python' not in list.

reverse() Method

Reverses the list.

SYNTAX:

list.reverse()

Example:

courseList = ['C', 'Java', 'PHP'] print("Before reverse():", courseList) courseList.reverse() print("After reverse():", courseList)

Output:

Before reverse(): ['C', 'Java', 'PHP'] After reverse(): ['PHP', 'Java', 'C']

sort() Method

Arranges the element in sorted order.

SYNTAX:

list.sort([reverse=BooleanValue])

sort() method have optional argument reverse whose default value is False which sort the elements in ascending order. For descending order assign value True to reverse argument.

Example1:

courseList = ['PHP', 'C', 'Java', 'Python'] print("Before sort():", courseList) courseList.sort() print("After sort():", courseList)

Output1:

Before sort(): ['PHP', 'C', 'Java', 'Python'] After sort(): ['C', 'Java', 'PHP', 'Python']

Example2:

courseList = ['PHP', 'C', 'Java', 'Python'] print("Before sort():", courseList) courseList.sort(reverse=True) print("After sort():", courseList)

Output2:

Before sort(): ['PHP', 'C', 'Java', 'Python'] After sort(): ['Python', 'PHP', 'Java', 'C']