getting_started/README.md

 Getting started
 ===============
 
-This directory contains the "Getting started" practical.
+
+This directory contains the _Getting started_ practical, intended for those of
+you who are new to Python as a language, or want a refresher on how it all
+works.
+
+
+If you are already comfortable with Python, `numpy`, `nibabel`, and `jupyter`.
+then you might want to check out the `advanced_topics` folder.
+
 
 1. Python basics (MJ)
 2. Text input/output (MC)
@@ -9,5 +17,5 @@ This directory contains the "Getting started" practical.
 4. Numpy (PM)
 5. Nifti images (MJ)
 6. Image manipulation (MC)
-7. Jupyter notebook and Ipython(MC)
+7. Jupyter notebook and IPython (MC)
 8. Writing a callable script (MJ)

talks/introduction/example_project/myscript.py

+#!/usr/bin/env fslpython
+
+# That first line up there ensures that your
+# script will be executed in the fslpython
+# environment. If you are writing a general
+# Python script, you should use this line
+# instead: #!/usr/bin/env python
+
+# In Python, we need to "import" libraries
+# (called modules) before we can use them.
+import sys
+import nibabel as nib
+
+# We can get to our command
+# line arguments via sys.argv
+fpath = sys.argv[1]
+
+# We can use nibabel to load
+# NIFTI images (and other
+# neuroimaging data formats)
+img = nib.load(fpath)
+data = img.get_data()
+
+# Now we're working with a
+# numpy array.
+nzmean = data[data != 0].mean()
+
+print('mean:', nzmean)