Package installed by Conda, Python cannot find it

问题

I try to install Theano by Anaconda. It works, but when I enter the python -i, import theano shows No module named 'theano'. Do I need to switch another interpreter of Python, how? Also, for the packages installed by conda, if I don't double install them, can I find in Python? How is Python related to Python by Anaconda? Thanks!!!

回答1:

I had have a similar issue, trying to install folium. If you are using the Anaconda:

When you install using conda install -c conda-forge folium, the package will be placed in:

./anaconda3/envs/[name env]/lib/python3.7/site-packages/folium

When you install using pip (with a anaconda env activated), pip install folium, the package will be placed in:

./anaconda3/lib/python3.7/site-packages/folium

Python use first the sites-packages as the target directory of manually built python packages. When you build and install python packages from source (using distutils, probably by executing python setup.py install ), you will find the installed modules in site-packages by default.

In this case you have two places: /anaconda3/lib/python3.7/site-packages/ and /anaconda3/envs/[name env]/lib/python3.7/site-packages/.

First the modules will be available as default in /anaconda3/lib/python3.7/site-packages/. Sometimes (and I really don't know why) the modules inside sites-packages conda env are not available to import automatically without export the PATH.

So, to solve this issue, you have 2 options:

• Installing using pip install folium and import folium (don't need install by conda install), or

• After conda install , run conda init, close the terminal and open a new one. So, try to import again.

Here are some tips about use a pip in a conda-environment.

回答2:

You can refer to a specific version of python by using the following at the first line of your .py file This is for python 2.7

#!/usr/bin/env python2.7

This is for python 3

#!/usr/bin/env python3

As other users already pointed out you need to check if your module is included in your sys path. Use code:

import sys
print(sys.path)

If not you can include this in your sys.path by using the command:

sys.path.append('/path/to/the/folder/of/your/module/file')

or place it in default PYTHONPATH itself.

Other great answers: https://stackoverflow.com/a/19305076/5381704

来源：https://stackoverflow.com/questions/39811929/package-installed-by-conda-python-cannot-find-it