'Raman_spectra' object has no attribute 'code'

This error message means that you are trying to access an attribute called 'code' on an object of type 'Raman_spectra', but that attribute does not exist within the 'Raman_spectra' class.

To solve this error, you should check the implementation of the 'Raman_spectra' class and make sure that the attribute 'code' is defined within it. If it is not defined, you may need to add it to the class definition or modify your code to use an existing attribute instead.