import tensorflow as tf from tensorflow import keras import numpy as np # 加载 IMDB 数据集 imdb = keras.datasets.imdb (train_data, train_labels), (test, test_labels) = imdb.load_data(num_words=00) # 将整数序列填充为相同的长度 train_data = keras.preprocessing.sequence.pad_sequences(train_data, value=0, padding='post', maxlen=256) test_data = keras.preprocessing.sequence.pad_sequences(test_data, value=0, padding='post', maxlen=256) # 构建模型 model = keras.Sequential() model.add(keras.layers.Embed(10000, 16)) model.add(keras.layers.GlobalAveragePooling1D()) model.add(keras.layers(16, activation=tf.nn.relu)) model.add(keras.layers.Dense(1, activation=tf.sigmoid)) # 编译模型 model.compile(optimizer='adam', loss='binary_crossentropy', metrics=['accuracy']) # 训练模型 history = model.fit(train_data, train_labels, epochs=40, batch_size=512, validation_data=(test_data, test_labels), verbose=1) # 在测试数据上评估模型 results = model.evaluate(test_data, test_labels) print('Test loss:', results[0]) print('Test accuracy:', results[1])test_data = keras.preprocessing.sequence.pad_sequences(test_data, value=0, padding='post', maxlen=256) NameError: name 'test_data' is not defined

这个错误的原因是在使用 `test_data` 变量之前没有定义它。你需要先加载测试数据集 `test_data`，然后再使用 `pad_sequences` 函数对其进行填充。

你可以尝试在以下代码中添加加载测试数据集的语句：

import tensorflow as tf 
from tensorflow import keras 
import numpy as np 

# 加载 IMDB 数据集
imdb = keras.datasets.imdb 
(train_data, train_labels), (test_data, test_labels) = imdb.load_data(num_words=10000) 

# 将整数序列填充为相同的长度
maxlen = 256
train_data = keras.preprocessing.sequence.pad_sequences(train_data, value=0, padding='post', maxlen=maxlen)
test_data = keras.preprocessing.sequence.pad_sequences(test_data, value=0, padding='post', maxlen=maxlen)

# 构建模型
model = keras.Sequential() 
model.add(keras.layers.Embedding(10000, 16)) 
model.add(keras.layers.GlobalAveragePooling1D()) 
model.add(keras.layers.Dense(16, activation=tf.nn.relu)) 
model.add(keras.layers.Dense(1, activation=tf.sigmoid)) 

# 编译模型
model.compile(optimizer='adam', loss='binary_crossentropy', metrics=['accuracy']) 

# 训练模型
history = model.fit(train_data, train_labels, epochs=40, batch_size=512, validation_data=(test_data, test_labels), verbose=1) 

# 在测试数据上评估模型
results = model.evaluate(test_data, test_labels) 
print('Test loss:', results[0]) 
print('Test accuracy:', results[1])

这样你就不会再遇到 `NameError: name 'test_data' is not defined` 错误了。