class_docstr: Regularization for Lasso Regression 
class_docstr_tok: ["Regularization","for","Lasso","Regression"]
code: def grad(self, w):
      return self.alpha * np.sign(w)
  
imports: from __future__ import print_function, division
  import numpy
  import math
  from mlfromscratch.utils import normalize, polynomial_features
label_desc: Use image node_id 3 for calling the l1_regularization obj's underlying member method code with example usage: obj.grad(w) and returns: unknown