I got exactly the same issue. I installed both python 3.6.3 in my anaconda "my_env" environment. I can import gensim in python terminal, but not in iPython.
(my_env) martin@nlpparser:~$ ipython
Python 3.6.3 |Anaconda, Inc.| (default, Oct 13 2017, 12:02:49)
Type 'copyright', 'credits' or 'license' for more information
IPython 6.1.0 -- An enhanced Interactive Python. Type '?' for help.
In [1]: import gensim
---------------------------------------------------------------------------
ModuleNotFoundError Traceback (most recent call last)
<ipython-input-1-ec15f3ffe0f1> in <module>()
----> 1 import gensim
ModuleNotFoundError: No module named 'gensim'
In contrast to this output successfully:
(my_env) martin@nlpparser:~$ python
Python 3.6.3 |Anaconda, Inc.| (default, Oct 13 2017, 12:02:49)
[GCC 7.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import gensim
>>>