Question

我有以下用于python 2.7的代码，但是当我升级到python 3.6时，map（）函数出错了

代码：

mods = ['BPSK', 'QPSK', '8PSK', 'PAM4', 'QAM16', 'QAM64', 'GFSK', 'CPFSK']
# X contain a dataset
p.random.seed(2017)
n_examples = X.shape[0]
n_train = int(n_examples * 0.5)
train_idx = np.random.choice(range(0,n_examples), size=n_train, replace=False)
test_idx = list(set(range(0,n_examples))-set(train_idx))
X_train = X[train_idx]
X_test =  X[test_idx]
def to_onehot(yy):
    yy1 = np.zeros([len(yy), max(yy)+1])
    yy1[np.arange(len(yy)),yy] = 1
    return yy1

Y_train = to_onehot(map(lambda x: mods.index(lbl[x][0]), train_idx))
Y_test = to_onehot(map(lambda x: mods.index(lbl[x][0]), test_idx))

错误：

Traceback (most recent call last):
  File "C:/Users/user/PycharmProjects/AMC/classification.py", line 46, in <module>
    Y_train = to_onehot(map(lambda x: mods.index(lbl[x][0]), train_idx))
  File "C:/Users/user/PycharmProjects/AMC/classification.py", line 42, in to_onehot
    yy1 = np.zeros([len(yy), max(yy)+1])
TypeError: object of type 'map' has no len()

我读过此answer，但我不知道如何在代码中修复

'map'类型的对象在python 3.6中没有len（）

0 个答案: