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How to check if a string is empty in Python

How to check if a string is empty in Python.

Here is a step-by-step tutorial on how to check if a string is empty in Python.

Step 1: Understanding an empty string​

In Python, an empty string is a string that doesn't contain any characters. It is represented by two quotation marks with no characters in between, like this: "".

Step 2: Using the len() function​

The len() function in Python returns the length of a string, which is the number of characters it contains. To check if a string is empty, we can use the len() function and compare its result to zero.

Here is an example:

string1 = ""
if len(string1) == 0:
    print("The string is empty.")
else:
    print("The string is not empty.")

Output:

The string is empty.

In this example, we create a string string1 that is empty. We pass string1 to the len() function, and if the length is equal to zero, we print "The string is empty." Otherwise, we print "The string is not empty."

Step 3: Using a comparison operator​

Instead of comparing the result of len() to zero, we can use a comparison operator directly to check if the string is empty.

Here is an example:

string2 = ""
if string2 == "":
    print("The string is empty.")
else:
    print("The string is not empty.")

Output:

The string is empty.

In this example, we compare string2 directly to an empty string "". If the comparison is true, we print "The string is empty." Otherwise, we print "The string is not empty."

Step 4: Using the not operator​

We can also use the not operator to check if a string is empty. By using not before a string, it will return True if the string is empty, and False otherwise.

Here is an example:

string3 = ""
if not string3:
    print("The string is empty.")
else:
    print("The string is not empty.")

Output:

The string is empty.

In this example, we use the not operator before string3. If string3 is empty, the not operator will return True, and we print "The string is empty." Otherwise, we print "The string is not empty."

Conclusion​

You have learned different ways to check if a string is empty in Python. You can use the len() function, comparison operators, or the not operator to determine if a string contains any characters or not.