model_params.json

{ "linear_regression": 
          {"sgdregressor__alpha": [0.0001,0.005,0.001,0.05,0.01,0.1,0.5,1]} ,
    
     "decision_tree":
          {"decisiontreeregressor__max_depth": [3,5,7,9,11,13,15,17,19,21]} ,
    
     "randomforest":
          {
         "randomforestregressor__max_depth": (1,10) ,
         "randomforestregressor__n_estimators": (3,50) ,
         } ,
    
     "xgboost" : 
          {"xgbregressor__max_depth":(1,10),
         "xgbregressor__n_estimators":(3,50),
         "xgbregressor__learning_rate":(0.1, .99, 'uniform'),
         "xgbregressor__subsample":(0.7, 1, 'uniform'),
         "xgbregressor__colsample_bytree":(0.7, 1, 'uniform'),
         "xgbregressor__lambda":(1e-4, 1e+3,'log-uniform'),
         "xgbregressor__scale_pos_weight":(0.15,.99,'uniform')}
  }