3 vÅÏ^Tã@s dd„ZdS)c Cs„yZt|tƒr|}n6t|tƒr8|jdƒ\}}||jƒf}n|jj|jjf}t|ƒdksXt ‚|St t fk r~t d|ƒ‚YnXdS)zã Take a model or a string of the form "app_label.ModelName" and return a corresponding ("app_label", "modelname") tuple. If a tuple is passed in, assume it's a valid model tuple already and return it unchanged. Ú.éz`Invalid model reference '%s'. String model references must be of the form 'app_label.ModelName'.N) Ú isinstanceÚtupleÚstrÚsplitÚlowerÚ_metaÚ app_labelÚ model_nameÚlenÚAssertionErrorÚ ValueError)ÚmodelZ model_tupler r ©rú:/usr/lib/python3.6/site-packages/django/db/models/utils.pyÚmake_model_tuples  rN)rrrrrÚs