How to limit gradient descent weights?

Question

Python

Here is the code for calculating the coefficient. I want to limit the weight in a range like (-1, 1) How to do it? Write a separate class?

def coefficients_sgd(train, l_rate, n_epoch):
  coef = [0.0 for i in range(len(train[0]))]
  for epoch in range(n_epoch):
    sum_error = 0
    for row in train:
      yhat = predict(row, coef)
      error = yhat - row[-1]
      sum_error += error**2
      coef[0] = coef[0] - l_rate * error
      for i in range(len(row)-1):
        coef[i + 1] = coef[i + 1] - l_rate * error * row[i]
    print('>epoch=%d, lrate=%.3f, error=%.3f' % (epoch, l_rate, sum_error))
  return coef