pl/python中的全局变量

以下代码在我的python ide中工作正常:

counter = 1000


def increment():
    global counter
    counter += 1


increment()
print(counter)

但是当我复制和粘贴一个pl/python函数中的代码(如下所示)时,它不起作用。

counter = 1000


def increment():
    global counter
    counter += 1


increment()
plpy.notice(counter)

返回的错误消息为:

ERROR:  NameError: name 'counter' is not defined
CONTEXT:  Traceback (most recent call last):
  PL/Python function "testing", line 9, in <module>
    increment()
  PL/Python function "testing", line 6, in increment
    counter += 1
PL/Python function "testing"