Python del Statement

by Online Tutorials Library July 14, 2022

Python del Statement

Introduction

In Python, the del keyword is generally used to delete an object. Since everything in Python represents some kind of object, the del keyword can also be used to delete lists, variables, parts of a list, etc. The del statement does not return any type of value.

Syntax of del statement

Note: del is a keyword, and obj_name can be lists, dictionaries, user-defined objects, variables, etc.

Examples of del Statement

Let’s look at some examples of del statements and try to delete some items.

Example 1: In this program we will delete a variable using del statement

  a = 13  b = 5  c = a + b + 13 – 1 + 5  print(c)    # delete the c variables  del c    # print c variable after delete  print(c)  

Output:

35    Traceback (most recent call last):    File "", line 10, in   NameError: name 'c' is not defined  >

Python del Statement

Example 2: In this program we will delete a list and slice list using del keyword

  items_1 = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]  items_2 =[“a”, “b”, “c”, “d”, “e”, “f”]    # print the items_1 and items_2  print(items_1)  print(items_2)    # delete the 3rd element of items_1  del items_1[2]    # check if the 3rd element in items_1 is deleted or not  print(items_1)    # slice items_1 from index 4 to 9  del items_1[4:9]    # check if the elements from index 4 to 9 in items_1 is deleted or not  print(items_1)    # delete the 2nd element of items_2  del items_2[1]    # check if the 2nd element in items_2 is deleted or not  print(items_2)    # delete items_2  del items_2    # check if items_2 exists  print(items_2)  

Output:

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]  ['a', 'b', 'c', 'd', 'e', 'f']  [0, 1, 3, 4, 5, 6, 7, 8, 9]  [0, 1, 3, 4]  ['a', 'c', 'd', 'e', 'f']    Traceback (most recent call last):    File "", line 30, in   NameError: name 'items_2' is not defined  >

Python del Statement

Example 3: In this program, we will use the del statement to delete dictionaries and key-value pairs

  dictionary_1 = {“up”: “down”, “forward”: “backward”, “small”: “down”}  dictionary_2 = {“short”: “long”, “you”: “me”, “Jack”: “John”}    # check if dictionary_1 and dictionary_2 exists  print(dictionary_1)  print(dictionary_2)    # delete key-value pair with key “up” from dictionary_1  del dictionary_1[“up”]    # check if the key-value pair with key “up” from dictionary_1 is deleted  print(dictionary_1)    # delete dictionary_2  del dictionary_2    # check if dictionary_2 exists  print(dictionary_2)  

Output:

{'up': 'down', 'forward': 'backward', 'small': 'down'}  {'short': 'long', 'you': 'me', 'Jack': 'John'}  {'forward': 'backward', 'small': 'down'}    Traceback (most recent call last):     File "", line 18, in   NameError: name 'dictionary_2' is not defined  >

Python del Statement

Example 4: Delete a User-Defined Object

  # defining a class  class employee:      name = “John wik”      age = 26      address = “C-26, London”      phone_no = 61562347      # declaring the object to the employee class  emp = employee()    # print the employee data  print(“Name: “, emp.name)  print(“Age: “, emp.age)  print(“Address: “, emp.address)  print(“Phone No: “, emp.phone_no)    # deleting the object   del emp    # printing values – will generate NameError  print(“Name: “, emp.name)  print(“Age: “, emp.age)  print(“Address: “, emp.address)  print(“Phone No: “, emp.phone_no)  

Output:

Name:  John wik  Age:  26  Address:  C-26, London  Phone No:  61562347  Traceback (most recent call last):     File "", line 21, in   NameError: name 'emp' is not defined  >

Python del Statement

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Python del Statement

Python del Statement

Introduction

Syntax of del statement

Note: del is a keyword, and obj_name can be lists, dictionaries, user-defined objects, variables, etc.

Examples of del Statement

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