ANN: New Book: Programming in Python 3

[Colin J. Williams]

Steve Holden wrote:
> Thomas Heller wrote:
>> Mark Summerfield schrieb:
>>> Just a follow-up to say that the book has now been published in the
>>> U.S.
>>> It is now in stock at InformIT, and should reach other stores, e.g.,
>>> Amazon, in a week or so.
>>>
>>> Also, the introduction, the first few pages of the first chapter, the
>>> whole of chapter 12 (regular expressions), and the index are now
>>> available for free download in a PDF from here:
>>> http://www.informit.com/store/product.aspx?isbn=0137129297
>> Question from a non-native english speaker: is this now valid english?
>>
>>   "One of Python’s great strengths"
>>                 ^
>>   "and also teaches Python’s functional programming features"
>>                           ^
>>   "The book’s approach is wholly practical"
>>            ^
> It always has been valid English. The apostrophe is only omitted from
> personal pronouns (hers, its, and so on).
> 
> regards
>  Steve

What is the subject of "teaches"?

I have no problem with the second sentence.

Colin W.