TypeError: fit() missing 1 required positional argument: 'y' site:stackoverflow.com code example

Example: reg.fit(x_train, y_train) TypeError: fit() missing 1 required positional argument: 'y'

reg = linear_model.LinearRegression() <--- #all i did was add parentheses

xTrain, xTest, yTrain, yTest = train_test_split(dfx, dfy, test_size=0.33, random_state=42)

reg.fit(xTrain, yTrain)