Why does Learn Python The Hard Way suggest to "Read your .py file backwards."?

I am reading Learn Python The Hard Way and I 开发者_Go百科am really curious what he means by

Read your .py file backwards

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Exercise 41 (page 117) explains it better. This snippet:

cities['_find']=find_city
city_found=cities['_find'](cities,state)

reads like this when read backwards:

1. state and city are...
2. passed as parameters to...
3. a function at...
4. _find inside...
5. the dict cities...
6. and finally assigned to city_found.

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Reading something backwards word-for-word is also a great proofreading technique.

Often, when reading something forwards, you'll skip past words as you'll be assuming what comes next. Reading something backwards allows you to spot spelling errors more effectively.