g_1 = tf.Graph()
with g_1.as_default():
  # Operations created in this scope will be added to `g_1`.
  c = tf.constant("Node in g_1")

  # Sessions created in this scope will run operations from `g_1`.
  sess_1 = tf.Session()

g_2 = tf.Graph()
with g_2.as_default():
  # Operations created in this scope will be added to `g_2`.
  d = tf.constant("Node in g_2")

# Alternatively, you can pass a graph when constructing a <a href="../api_docs/python/tf/Session"><code>tf.Session</code></a>:
# `sess_2` will run operations from `g_2`.
sess_2 = tf.Session(graph=g_2)

assert c.graph is g_1
assert sess_1.graph is g_1

assert d.graph is g_2
assert sess_2.graph is g_2

#要检查当前的默认图，请调用 tf.get_default_graph，它会返回一个 tf.Graph 对象：
# Print all of the operations in the default graph.
g = tf.get_default_graph()
print(g.get_operations())