ModuleNotFoundError: No module named 'autoreload' - python-3.x

Question

I run the following code from convolutional neural network tutorials on jupyter notebook with python 3 kernel, and got the ModuleNotFoundError: No module named 'autoreload';
import numpy as np
import h5py
import matplotlib.pyplot as plt
%matplotlib inline
plt.rcParams['figure.figsize'] = (5.0, 4.0) # set default size of plots
plt.rcParams['image.interpolation'] = 'nearest'
plt.rcParams['image.cmap'] = 'gray'
%load_ext autoreload
%autoreload 2
np.random.seed(1)
---------------------------------------------------------------------------
ModuleNotFoundError Traceback (most recent call last)
<ipython-input-1-3d0ea63c7843> in <module>()
8 plt.rcParams['image.cmap'] = 'gray'
9
---> 10 get_ipython().magic('load_ext autoreload # reload modules before executing user code')
11 get_ipython().magic('autoreload 2 # Reload all modules (except those excluded by %aimport)')
12
/opt/conda/lib/python3.6/site-packages/IPython/core/interactiveshell.py in magic(self, arg_s)
2156 magic_name, _, magic_arg_s = arg_s.partition(' ')
2157 magic_name = magic_name.lstrip(prefilter.ESC_MAGIC)
-> 2158 return self.run_line_magic(magic_name, magic_arg_s)
2159
2160 #-------------------------------------------------------------------------
/opt/conda/lib/python3.6/site-packages/IPython/core/interactiveshell.py in run_line_magic(self, magic_name, line)
2077 kwargs['local_ns'] = sys._getframe(stack_depth).f_locals
2078 with self.builtin_trap:
-> 2079 result = fn(*args,**kwargs)
2080 return result
2081
<decorator-gen-62> in load_ext(self, module_str)
/opt/conda/lib/python3.6/site-packages/IPython/core/magic.py in <lambda>(f, *a, **k)
186 # but it's overkill for just that one bit of state.
187 def magic_deco(arg):
--> 188 call = lambda f, *a, **k: f(*a, **k)
189
190 if callable(arg):
/opt/conda/lib/python3.6/site-packages/IPython/core/magics/extension.py in load_ext(self, module_str)
35 if not module_str:
36 raise UsageError('Missing module name.')
---> 37 res = self.shell.extension_manager.load_extension(module_str)
38
39 if res == 'already loaded':
/opt/conda/lib/python3.6/site-packages/IPython/core/extensions.py in load_extension(self, module_str)
81 if module_str not in sys.modules:
82 with prepended_to_syspath(self.ipython_extension_dir):
---> 83 __import__(module_str)
84 mod = sys.modules[module_str]
85 if self._call_load_ipython_extension(mod):
ModuleNotFoundError: No module named 'autoreload'
I just couldn't find any solution on this issue. How should I fix this error?

Answer 1

The module autoreload belongs to the library IPython, which is running in the background on Jupyter.
The same error occurred to me and it was due to a blank space, see:
.
So make sure that there are no spaces at the end of the command!

Answer 2

I hit this same error because I had a comment after the magic command:
bad:
%load_ext autoreload # this comment should be removed
good:
%load_ext autoreload