How to Check Empty String in Python

Brief about string

A string is a sequence of characters in a programming language, such as Python. They are commonly used to store text-based data and can be manipulated using various string methods and operations. Strings are typically enclosed in quotation marks (single or double) and can contain letters, numbers, symbols, and spaces. Examples of strings in Python include: 'hello', "world", '12345', "I am a string".

Determine if a string is empty

In Python, you can determine if a string is empty by checking if its length is equal to 0, or by checking if it’s equal to the empty string ''. For example:

string = ''
if len(string) == 0:
    print("The string is empty")
elif string == '':
    print("The string is empty")
else:
    print("The string is not empty")

Check an ‘array’ is empty

In Python, you can check if an array (or list) is empty using the ‘len()‘ function or by checking the array’s boolean value.

Here’s an example using the ‘len()‘ function:

my_array = []
if len(my_array) == 0:
    print("The array is empty.")
else:
    print("The array is not empty.")

In this example, the ‘len()‘ function is used to get the number of elements in the ‘my_array‘ list. If the length of the list is 0, the array is considered empty, and the code will print “The array is empty.” Otherwise, the code will print “The array is not empty.”

Here’s another example using the boolean value of the array:

my_array = []
if not my_array:
    print("The array is empty.")
else:
    print("The array is not empty.")

In this example, the boolean value of the ‘my_array‘ list is checked using the ‘not‘ keyword. If the list is empty, its boolean value is ‘False‘, so the code will print “The array is empty.” Otherwise, the code will print “The array is not empty.”

Note that you can use this same method with any iterable object, not just arrays or lists. If the object is empty, its boolean value will be ‘False‘.

Check empty ‘queue’ in python

In Python, you can check if a queue is empty using the ‘qsize()‘ method or by checking the queue’s boolean value.

Here’s an example using the ‘qsize()‘ method:

import queue

my_queue = queue.Queue()
if my_queue.qsize() == 0:
    print("The queue is empty.")
else:
    print("The queue is not empty.")

In this example, the ‘Queue()‘ class from the ‘queue‘ module is used to create a new queue object ‘my_queue‘. The ‘qsize()‘ method is used to get the number of elements in the queue. If the size of the queue is 0, the queue is considered empty, and the code will print “The queue is empty.” Otherwise, the code will print “The queue is not empty.”

Here’s another example using the boolean value of the queue:

import queue

my_queue = queue.Queue()
if my_queue.empty():
    print("The queue is empty.")
else:
    print("The queue is not empty.")

In this example, the ‘empty()‘ method of the ‘Queue()‘ class is used to check the boolean value of the queue. If the queue is empty, its boolean value is ‘True‘, so the code will print “The queue is empty.” Otherwise, the code will print “The queue is not empty.”

Note that this method can be used with any queue object, not just those created using the ‘queue‘ module. If the queue is empty, its boolean value will be ‘True‘.