我试过
%tensorflow_version 1.15
我几天前使用过这段代码，但从今天起它就不再起作用了。
结果是
ValueError Traceback (most recent call last)
<ipython-input-6-24c52e77c597> in <module>()
----> 1 get_ipython().magic('tensorflow_version 1.15')
2 frames
/usr/local/lib/python3.7/dist-packages/IPython/core/interactiveshell.py in magic(self, arg_s)
2158 magic_name, _, magic_arg_s = arg_s.partition(' ')
2159 magic_name = magic_name.lstrip(prefilter.ESC_MAGIC)
-> 2160 return self.run_line_magic(magic_name, magic_arg_s)
2161
2162 #-------------------------------------------------------------------------
/usr/local/lib/python3.7/dist-packages/IPython/core/interactiveshell.py in run_line_magic(self, magic_name, line)
2079 kwargs['local_ns'] = sys._getframe(stack_depth).f_locals
2080 with self.builtin_trap:
-> 2081 result = fn(*args,**kwargs)
2082 return result
2083
/usr/local/lib/python3.7/dist-packages/google/colab/_tensorflow_magics.py in _tensorflow_version(line)
39
40 Your notebook should be updated to use Tensorflow 2.
---> 41 …