text: import numpy as np
  import gzip
  import pickle as cPickle
  
  
  def load_usps(all_use=False):
      f = gzip.open('data/usps_28x28.pkl', 'rb')
      data_set = cPickle.load(f)
      f.close()
      img_train = data_set[0][0]
      label_train = data_set[0][1]
      img_test = data_set[1][0]
      label_test = data_set[1][1]
      inds = np.random.permutation(img_train.shape[0])
      if all_use == 'yes':
          img_train = img_train[inds][:6562]
          label_train = label_train[inds][:6562]
      else:
          img_train = img_train[inds][:1800]
          label_train = label_train[inds][:1800]
      img_train = img_train * 255
      img_test = img_test * 255
      img_train = img_train.reshape((img_train.shape[0], 1, 28, 28))
      img_test = img_test.reshape((img_test.shape[0], 1, 28, 28))
      return img_train, label_train, img_test, label_test
  