The Functions and Methods in List

A function in python is a built-in function which is available to use at any time.

The function is applicable for all kind of datatypes in python, that means these are applicable for List, Tuple, strings, etc..

The Functions are directly called and not on any objects in python and also we can pass the arguments by using the function and function returns the data as a result.

We can define the function by using the def keyword and call it by using the parenthesis

def my-function():
print("Hello")

The Output is:
We can pass the list as a parameter

def my_function(food):
  for x in food:
    print(x)
fruits = ["apple", "banana", "cherry"]
my_function(fruits)

list-functions-one

The List of python built-in functions are as follow:

Functions Description
Python abs() returns the absolute value of a number
Python all() returns true when all elements in iterable are true
Python any() Checks if any Element of an Iterable is True
Python ASCII() Returns String Containing Printable Representation
Python bin() converts an integer to a binary string
Python bool() Converts a Value to Boolean
Python bytearray() returns array of given byte size
Python bytes() returns an immutable bytes object
Python callable() Checks if the Object is Callable
Python Chr()
Returns a Character (a string) from an Integer
Python classmethod()
returns class method for a given function
Python compile()
Returns a Python code object
Python complex()
Creates a Complex Number
Python delattr()
Deletes Attribute From the Object
Python dict()
Creates a Dictionary
Python dir()
Tries to Return Attributes of Object
Python divmod()
Returns a Tuple of Quotient and Remainder
Python enumerate()
Returns an Enumerate Object
Python eval()
Runs Python Code Within Program
Python exec()
Executes Dynamically Created Program
Python filter() constructs iterator from elements which are true
Python float()
returns floating-point number from number, string
Python format()
returns a formatted representation of a value
Python frozenset()
returns immutable frozenset object
Python getattr()
returns value of a named attribute of an object
Python globals()
returns dictionary of the current global symbol table

A method in python is similar to the function except that it is associated with an object/classes.

A method is implicitly used for an object for which it is called.

The following table contains all the list Methods:

Methods Description
Python List append() Add Single Element to The List
Python List extend() Add Elements of a List to Another List
Python List insert() Inserts Element to The List
Python List remove() Removes Element from the List
Python List index() Returns smallest index of the element in the list
Python List count() Returns occurrences of an element in a list
Python List pop() Removes Element at Given Index
Python List reverse() Reverses a List
Python List sort() Sorts elements of a list
Python List copy() Returns Shallow Copy of a List
Python List clear() Removes all items from the List
Python any() Checks if any Element of an Iterable is True
Python all() Returns true when all elements in iterable are true
Python ASCII() Returns String Containing Printable Representation
Python bool() Converts a Value to Boolean
Python enumerate() Returns an Enumerate Object
Python filter() Constructs iterator from elements which are true
Python iter() Returns iterator for an object
Python list() The function creates a list in Python
Python len() Returns Length of an Object
Python max() Returns largest element
Python min() Returns smallest element
Python map() Applies Function and Returns a List
Python reversed() Returns reversed iterator of a sequence
Python slice() Creates a slice object specified by range()
Python sorted() Returns sorted the list from a given iterable
Python sum() Add items of an Iterable
Python zip() Returns an Iterator of Tuples

The append() method is used to add the element to the given list at the end.
The syntax for the append() method is

list.append()

Example:

List=[10,20,30]
List.append(40)
print(List)
##The output is:
[10, 20, 30, 40]

The following program is to add the elements from 1 to 100 to the list by using the append() method, which is divisible by 10.

List=[]
for x in range(1,101):
    if x%10==0:
        List.append(x)
print(List)
##The output is:
[10, 20, 30, 40, 50, 60, 70, 80, 90, 100]

The insert() method is used to add the element to the given list at the specified index.
The syntax for the insert() method is

list.insert(index,element)

Example:

List=[10,20,30,40,50]
List.insert(1,100)
print(List)

adding-element-by-using-insert-method-one

If the specified index is greater than the maximum index present in the list, then the element is added at the end of the list.

List=[10,20,30,40,50]
List.insert(60,100)
print(List)

if-secified-index-greater-than-maxindex

If the specified index is less than the minimum index, then the element is added at the beginning of the list.

List=[10,20,30,40,50]
List.insert(-60,100)
print(List)

if-specified-index-is-less-than-present-index

The extend() method is used to add all the elements to the list in the same sequence

The syntax for the extend() method is

list_one.extend(List_two)

Example:

List_one=["fruits","veggies","flower"]
List_two=["grains","fibers"]
List_one.extend(List_two)
print(List_one)

extend-method

The remove() method is used to remove a specified element from the list

The syntax for the remove() method is

list.remove(x)

Example:

List=[10,20,10,20,40]
List.remove(40)
print(List)

remove-method

If the specified element is present multiple times, then the python will remove the first occurrence of the element.

List=[10,20,10,20,40]
List.remove(10)
print(List)

removing-first-occurence-element

If the specified element is not present in the list then the remove() method will throw a value error.

The following example demonstrates the remove() method

List=[1,2,3,4,5,6]
print("Before Removal:",List)
element=int(input("Enter value to remove:"))
if element in List:
    List.remove(element)
    print("After Removal:",List)
else:
    print(element,"not available in the list")

program-to-remove-element

The following example demonstrates how to remove all the occurrences of an element present in the given list.

List=[1,1,1,1,2,2,2,3,3]
print("Before Removal:",List)
element=int(input("Enter value to remove:"))
while True:
    if element in List:
        List.remove(element)
    else:
        break
print("After Removal:",List)

removing-occurences-of-an-element

If we try to remove an element, which is not present in the list then the output is:

removing-occurences-of-an-element-one
The pop() method is used to remove an element present at the end of the list and returns the removed element.

The syntax for the pop() method is

list.pop()

Example:

List=[10,20,30,40,50,60]
List.pop()
print(List)
##The output is:
[10,20,30,40,50]

removing-element-by-using-pop-method

If we try to remove an element which is not present in the given list and if we apply pop() method to an empty list, then pop() method will throw an index error.

List=[10,20,30,40,50,60]
List.pop(70)
print(List)
##The output is:
Traceback (most recent call last):
  File "C:UsersAnup kumareclipse-workspaceFirstProjectPythonFirstPythonPackageFirstPythonModule.py", line 2, in <module>
    List.pop(70)
IndexError: pop index out of range

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