Item #37: Inner for loop should be indented

[panos73]

First of all, thanks for a really great book. In the online version of the book, https://learning.oreilly.com/library/view/effective-python-90/9780134854717/ch05.xhtml#ch5 it is correctly mentioned "—the average_grade method now has a loop within a loop and is difficult to read", but the indentation does not reflect in the code.

[cihati]

[bslatkin]

This appears to be the same root cause as issue #63.

[bslatkin]

Duplicate of #63