In ipython Python 2.7.11 |Anaconda 2.4.1 (64-bit) IPython 3.1.0 -- An enhanced Interactive Python. In [1]: import google.protobuf In [2]: However in python: Python 2.7.11 |Anaconda 2.4.1 (64-bit) >>> import google.protobuf Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named protobuf >>> Why this strange error happened? Please help me figure out. Continue reading...