Use of an undefined placeholder variable¶
This place-holder variable may not be defined. If this code is executed and the variable is undefined then a
NameError will occur.
Check that the name of the place-holder variable is not a typographic error. If the name is correct, either define a value for the variable, or import the module that defines the function or method that sets the value.
If another module initializes this variable before it is used, then the
NameError may not occur. However, you can make the code more robust and clearer by setting the variable to a default value in its own module.
Python Standard Library: NameError.