TensorFlow：变量范围内的未设置'reuse'

Question

是否有办法在变量范围内取消设置reuse ?我尝试了以下命令:

In [1]: import tensorflow as tf
In [2]: tf.get_variable_scope().reuse
Out[2]: False
In [3]: tf.get_variable_scope().reuse_variables
Out[3]: <bound method VariableScope.reuse_variables of <tensorflow.python.ops.variable_scope.VariableScope object at 0x7fd9cc46c4d0>>
In [4]: tf.get_variable_scope().reuse_variables()
In [5]: tf.get_variable_scope().reuse
Out[5]: True
In [6]: tf.get_variable_scope().reuse_variables()
In [7]: tf.get_variable_scope().reuse
Out[7]: True
In [8]: tf.get_variable_scope().reuse_variables(False)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-8-ba19ed12625c> in <module>()
----> 1 tf.get_variable_scope().reuse_variables(False)
TypeError: reuse_variables() takes exactly 1 argument (2 given)
In [9]: tf.get_variable_scope().reuse = False
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-9-ddd0b37e4f0e> in <module>()
----> 1 tf.get_variable_scope().reuse = False
AttributeError: can't set attribute
In [10]: tf.get_variable_scope().reuse_variables = False
In [11]: tf.get_variable_scope().reuse_variables()
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-11-d03dc0fb25b6> in <module>()
----> 1 tf.get_variable_scope().reuse_variables()
TypeError: 'bool' object is not callable

正如你所看到的，我不能通过调用reuse_variables偶数次来取消设置reuse，我不能用=操作符设置它，由于某种原因，我可以设置任何我想要的reuse_variables函数(这是一个bug吗?)。

Answer 1

一旦你进入一个作用域，我认为这是设计的，你不能改变重用状态，直到你重新打开作用域，以另一种方式设置标志:

with tf.variable_scope("scope"):
    a = tf.get_variable("var_a", 1) 
    print(a.name)
with tf.variable_scope("scope", reuse = True):
    b = tf.get_variable("var_a")
    print b.name 
    #c = tf.get_variable("var_b") # won't work
    # can't reuse something that doesn't exist
    # probably enforced so you don't make unintended variables
with tf.variable_scope("scope"): #reuse False
    #c = tf.get_variable("var_a") # won't work
    # there is another variable with the same name
    # makes sure you don't override the previous variable                    
    c = tf.get_variable("var_b",2)
    print c.name

你可以这样修改:

with tf.variable_scope("scope") as scope:
    a = tf.get_variable("var_a", 1)  
    print(a.name)
with tf.variable_scope("scope", reuse = True):
    b = tf.get_variable("var_a")
    print b.name 
    with tf.variable_scope(scope):
        c = tf.get_variable("var_b", 1)
        print c.name

我想你可以这样做:

print(tf.get_variable_scope().reuse) #False
tf.get_variable_scope().reuse_variables()
print(tf.get_variable_scope().reuse) #True
with tf.variable_scope(tf.get_variable_scope(), reuse=False):
    print(tf.get_variable_scope().reuse) #False