扩充keras模型输出，并将其作为第二个模型的输入

from tensorflow.keras.models import Model
from tensorflow.keras.layers import Dense, Input

# 定义第一个模型
input_layer = Input(shape=(input_dim,))
hidden_layer = Dense(hidden_units, activation='relu')(input_layer)
output_layer = Dense(output_dim, activation='softmax')(hidden_layer)

model1 = Model(inputs=input_layer, outputs=output_layer)

# 定义第二个模型，将第一个模型的输出作为输入
input_model1 = Input(shape=(output_dim,))
hidden_model1 = Dense(hidden_units, activation='relu')(input_model1)
output_model1 = Dense(output_dim, activation='softmax')(hidden_model1)

model2 = Model(inputs=input_model1, outputs=output_model1)

# 连接两个模型
output_model1 = model1(input_model1)
combined_model = Model(inputs=input_layer, outputs=output_model1)