How do you represent an empty string in Python?
In some applications, it is compulsory to fill data into an input field. In such cases, they are marked with an asterisk Show
In a simple form on any website, when a user tries to fill in the next field of data without filling the compulsory field or when the user tries to Submit/Save the page/form without filling in the compulsory field(s), it throws a warning which indicates that one/more of the compulsory fields haven't been filled. This is usually implemented by checking if the data entered by the user is empty or not. In Python, this could be done in many ways. They are listed below: 1. Using the not operator with the if conditionThe Programming Recommendations (PEP 8) suggests that the This can be used for lists and tuples as well. A non-empty string evaluates to True when used with an Let's take an example and see,
Output: The string is empty Here is another example showing how a non-empty string is evaluated.
Output: The string is not empty So, you can use a simple if-else condition too,
but it makes more sense code-wise to use the 2. Using the strip methodSometimes, a string might contain blank spaces, which makes it non-empty. Hence while checking for an empty string we also need to check whether the string has only spaces. This can be done using the Let's take an example where
we will be using the
Output: True True True False The above code can also be written as follows(more PYTHONIC way), which would give the same output as the above code,
3. Using the __eq__ methodThe
Output: Non-empty string Let's run the above code with an empty string,
Output: Empty string 4. Using the len methodThe
Output: Non-empty String 5. Using the strip method onlyThe
Output: It is either empty or blank Let's take another example:
Output: It is neither empty nor blank Note: Strings being empty and strings being blank are two different things. An empty string is when the string doesn't have any character, whitespace whatsoever. On the other hand, a blank string means a string that has multiple white spaces or tab spaces. In the above example, both the conditions are being checked for. ConclusionIn this post, we saw how a string can be checked for being empty or full of whitespaces using various different ways in python. If you think we missed something, do share your way of doing it in the comment section below. You may also like:
How do you represent an empty string?An empty string is represented as "" . It is a character sequence of zero characters. A null string is represented by null . It can be described as the absence of a string instance.
How do you represent empty in Python?[] This denotes an empty list. So, by comparing our list object to [], we can determine whether the list is empty or not.
How do you handle an empty string in Python?Use len to Check if a String in Empty in Python
# Using len() To Check if a String is Empty string = '' if len(string) == 0: print("Empty string!") else: print("Not empty string!") # Returns # Empty string! Keep in mind that this only checks if a string is truly empty.
How do you declare an empty string variable in Python?Defining empty variables in Python is straightforward. If you wish to define a placeholder for a missing value that will not be used for calculations, you can define an empty variable using the None keyword. This is useful because it clearly indicates that the value for a variable is missing or not valid.
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