set_parameters.py

# Copies one set of variables to another.
# Used to set worker network parameters to those of global network.
def update_target_graph(from_scope,to_scope):
    from_vars = tf.get_collection(tf.GraphKeys.TRAINABLE_VARIABLES, from_scope)
    to_vars = tf.get_collection(tf.GraphKeys.TRAINABLE_VARIABLES, to_scope)

    op_holder = []
    for from_var,to_var in zip(from_vars,to_vars):
        op_holder.append(to_var.assign(from_var))
    return op_holder

class Worker():
    def __init__(self,game,name,s_size,a_size,trainer,saver,model_path):
        ....
        ....
        ....
        #Create the local copy of the network and the tensorflow op to copy global paramters to local network
        self.local_AC = AC_Network(s_size,a_size,self.name,trainer)
        self.update_local_ops = update_target_graph('global',self.name)