ImportError cannot import name BytesIO when import caffe on ubuntu

Question

I am trying to make caffe running on my machine equipped with Ubuntu 12.04LTS. After finishing all the steps on the Installation page, I trained the LeNet model successfully and tried to use it as the tutorial from here. Then I got the following error:

Traceback (most recent call last): 
    File "<string>", line 1, in <module>
ImportError: No module named caffe
Error in sys.excepthook:
Traceback (most recent call last):
    File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 66, in apport_excepthook
      from apport.fileutils import likely_packaged, get_recent_crashes
    File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
      from apport.report import Report
    File "/usr/lib/python2.7/dist-packages/apport/report.py", line 18, in <module>
      import problem_report
    File "/usr/lib/python2.7/dist-packages/problem_report.py", line 14, in <module>
      import zlib, base64, time, sys, gzip, struct, os
    File "/usr/lib/python2.7/gzip.py", line 10, in <module>
      import io
    File "${HOME}/path/to/caffe/python/caffe/io.py", line 2, in <module>
      import skimage.io
    File "/usr/local/lib/python2.7/dist-packages/skimage/io/__init__.py", line 11, in <module>
      from ._io import *
    File "/usr/local/lib/python2.7/dist-packages/skimage/io/_io.py", line 1, in <module>
      from io import BytesIO
ImportError: cannot import name BytesIO

Original exception was:
Traceback (most recent call last): 
    File "<string>", line 1, in <module>
ImportError: No module named caffe

I set the PYTHONPATH in .bashrc file before I did the above. What is the problem? Could anyone give some hint? I am really confused. After running the command python -c 'import io; print io.__file__'in the very directory:

Traceback (most recent call last): 
    File "${HOME}/path/to/caffe/python/caffe/io.py", line 2, in <module>
      import skimage.io
    File "/usr/local/lib/python2.7/dist-packages/skimage/io/__init__.py", line 11, in <module>
      from ._io import *
    File "/usr/local/lib/python2.7/dist-packages/skimage/io/_io.py", line 1, in <module>
      from io import BytesIO
ImportError: cannot import name BytesIO
Error in sys.excepthook:
Traceback (most recent call last):
    File "/usr/lib/python2.7/dist-packages/apport_python_hook.py", line 66, in apport_excepthook
      from apport.fileutils import likely_packaged, get_recent_crashes
    File "/usr/lib/python2.7/dist-packages/apport/__init__.py", line 1, in <module>
      from apport.report import Report
    File "/usr/lib/python2.7/dist-packages/apport/report.py", line 18, in <module>
      import problem_report
    File "/usr/lib/python2.7/dist-packages/problem_report.py", line 14, in <module>
      import zlib, base64, time, sys, gzip, struct, os
    File "/usr/lib/python2.7/gzip.py", line 10, in <module>
      import io
    File "${HOME}/path/to/caffe/python/caffe/io.py", line 2, in <module>
      import skimage.io
    File "/usr/local/lib/python2.7/dist-packages/skimage/io/__init__.py", line 11, in <module>
      from ._io import *
    File "/usr/local/lib/python2.7/dist-packages/skimage/io/_io.py", line 1, in <module>
      from io import BytesIO
ImportError: cannot import name BytesIO

Original exception was:
Traceback (most recent call last): 
    File "${HOME}/path/to/caffe/python/caffe/io.py", line 2, in <module>
      import skimage.io
    File "/usr/local/lib/python2.7/dist-packages/skimage/io/__init__.py", line 11, in <module>
      from ._io import *
    File "/usr/local/lib/python2.7/dist-packages/skimage/io/_io.py", line 1, in <module>
      from io import BytesIO
ImportError: cannot import name BytesIO

So, the problem becomes to: how to solve the name issue? P.S.: I also inserted an issue at the repository of caffe.

Answer 1

You appear to have a package or module named io in your Python path that is masking the standard library package. It is imported instead but doesn't have a BytesIO object to import.

Try running:

python -c 'import io; print io.__file__'

in the same location you are running the tutorial and rename or move the file named by that import, presuming it is not the standard library version (ending in lib/python2.7/io.pyc).

It could be you set your Python path to the wrong directory. You should include path/to/caffe/python, not path/to/caffe/python/caffe, nor should you try and run python with the latter as your current working directory. In both cases caffe/python/caffe/io.py instead of the standard library version.

The installation instructions are not at fault here; they clearly tell you to use:

export PYTHONPATH=/path/to/caffe/python:$PYTHONPATH

Note the lack of /caffe at the end of that path.