In Python, sometimes it makes sense to declare a variable and not assign a value. To declare a variable without a value in Python, use the value “None”.
variable_without_value = None
You can also use what Python calls “type hints” to declare a variable without a value.
variable_without_value: str #variable with type string with no value
When working with variables in Python, sometimes it makes sense to initialize a variable, but not assign it any value.
While Python is dynamic and you don’t need to declare a variable until you’re going to assign a value to them or use them, it’s possible to define a variable without a value in a few ways.
The first way is to assign a variable to the value “None”.
variable_without_value = None print(variable_without_value) #Output: None
In this case, make sure that when you set the variable to None that is what you want to do. In some cases, it might lead to an incorrect value when you go to use the variable later in your program.
The second way is to use what Python calls “type hints”. The problem here is that the variable isn’t defined, but does exist in your program.
variable_without_value: str #variable with type string with no value print(variable_without_value) #Output: Traceback (most recent call last): File https://extendsclass.com/lib/Brython-3.8.9/www/src/Lib/site-packages/editor.py, line 116, in run exec(src, ns) File <string>, line 3, in <module> NameError: name 'variable_without_value' is not defined
Hopefully this article has been useful for learning how to declare variables without values in Python.
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