Merge pull request #649 from flow-project/improve-tutorials

add common error fix to tutorials README

tutorials/README.md

@@ -26,7 +26,7 @@ modified in order to prevent any exceptions from being raised. Throughout these
 exercises, you may find the
 [Flow documentation](https://flow.readthedocs.io/en/latest/) helpful.
 
-> **Note:** if, when running a notebook, you run into an error of the form
+> **Common error:** if, when running a notebook, you run into an error of the form
 > `ImportError: No module named flow.something`, this probably means that the
 > `flow` Conda environment is not active in your notebook. Go into the
 > [Conda tab](https://stackoverflow.com/questions/38984238/how-to-set-a-default-environment-for-anaconda-jupyter)
@@ -36,6 +36,14 @@ exercises, you may find the
 > solutions [here](https://stackoverflow.com/questions/39604271/conda-environments-not-showing-up-in-jupyter-notebook)
 > , or you can launch a Jupyter notebook using the `flow` environment directly
 > from the [Anaconda Navigator](https://docs.anaconda.com/anaconda/navigator/).
+> If you have the conda tab but you still get the error, open a new terminal
+> and execute the following commands:
+> ```
+> cd /
+> source activate flow
+> python
+> ```
+> (`cd /` is to make sure that `flow` is not in the folder you run `python` from). Then, in the Python interface that opens, run `import flow`. If you get an `ImportError`, this means you haven't installed Flow in your environment. Go back to the [installation instructions](https://flow.readthedocs.io/en/latest/flow_setup.html), especially the part where you do `pip install -e .` after having done `source activate flow`.
 
 The content of each exercise is as follows: