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For 2023 (and 2024 ...) - we are now fully retired from IT training.
We have made many, many friends over 25 years of teaching about Python, Tcl, Perl, PHP, Lua, Java, C and C++ - and MySQL, Linux and Solaris/SunOS too. Our training notes are now very much out of date, but due to upward compatability most of our examples remain operational and even relevant ad you are welcome to make us if them "as seen" and at your own risk.

Lisa and I (Graham) now live in what was our training centre in Melksham - happy to meet with former delegates here - but do check ahead before coming round. We are far from inactive - rather, enjoying the times that we are retired but still healthy enough in mind and body to be active!

I am also active in many other area and still look after a lot of web sites - you can find an index ((here))
The road ahead - Python 3

A couple of days ago, I mentioned Python 3 in general terms - and today I'm starting to flesh out the road ahead.


The print operator in Python was always a bit curious, with the trailing comma to signify "no new line" ... and that has been replaced by a print function, with named parameters for the end of line action, parameter separator, and output file - it's much more flexible in it sown right, and it allows you to override the printg function which you could not do with an operator. Here are some sample print function calls:

print (teeth,"teeth and",coal,"shoes")
print (teeth,"teeth and",coal,"shoes",sep = " - ")
print (teeth,"teeth and",end = "")
print (coal,"shoes")
print ("Error and logging message",file = sys.stderr)

See complete Python 3 example and Python 2 equivalent

input and raw_input

The input function, which used to process what the user typed through the Python interpreter has gone (thank goodness!) and the old raw_input functionality, that did what we wanted 99.9% of the time for input has now simply been named input. This will be short term confusing, but a big relief in the medium and long term.

See complete Python 3 example and Python 2 equivalent

range and xrange

The original range function - many moons ago - returned a list, which you could then step through in a for loop. Which was great for a small list and really grotty for a longer one - rather like blowing up a balloon (generating a list) and then letting the air out of it slowly. And of course, if you blow a balloon up too much it bursts! The xrange function was added to provide an iterator - rather than blowing up a balloon, the information is generated just-in-time, very much like a generator

Moving on to Python 3, range is now a generator (and xrange has gone), which means that it will default to being tidy. The same applies to things like map as well, and you will need to add a list function call there if you don't want to iterate through a mapping

Here's a generator in use (in Python 3) with the range function itself producing an iterator:

def squares(g):
  for val in range(g):
    print ("working out ",val)
    yield val*val
for ref in squares(8):
  print ("Board with ",ref," squares")

and here is what that code would look like on Python 2:

def squares(g):
  for val in xrange(g):
    print "working out ",val
    yield val*val
for ref in squares(8):
  print "Board with ",ref," squares"

Our next public Python Course will include a module on Python 3 changes, covering not only the new features, but also the way to make best use of them and to plan for them and easily convert from legacy Python code - moving Python forward on a practical basis. In due course (estimate - 3 to 6 months, depending on market requirements) the whole course will be Python 3 based.

We can also provide a one day seminar for current python users, introducing them to the new facilities and changes and helping them plan a painless transition for the way forward. Please email me for details.
(written 2008-09-10, updated 2008-09-11)

Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
Y300 - Python 3 - What is new, what's changed and why
  [753] Python 3000 - the next generation - (2006-06-09)
  [1788] Python 2 to Python 3 / Python 3000 / Py3k - (2008-09-07)
  [2277] Python classes / courses - what version do we train on? - (2009-07-10)
  [2285] Great new diagrams for our notes ... Python releases - (2009-07-13)
  [2559] Moving the product forward - ours, and MySQL, Perl, PHP and Python too - (2010-01-01)
  [2778] Learning to program in Python 2 ... and / or in Python 3 - (2010-05-24)
  [2871] Moving from Python 2.6 to Python 3 - (2010-07-14)
  [4469] Sorting in Python 3 - and how it differs from Python 2 sorting - (2015-04-20)
  [4470] Testing in Python 3 - unittest, doctest and __name__ == __main__ too. - (2015-04-21)
  [4590] Progress on moving from Python 2 to Python 3 - training for both versions - (2015-12-01)
  [4649] Object and Static methods - what is the difference; example in Python 3 - (2016-02-17)
  [4650] Why populate object with values as you construct them? - (2016-02-18)
  [4711] Convering from Python 2 to Python 3 - an update, and the 2to3 utility - (2016-10-30)
  [4712] A reminder of the key issues to consider in moving from Python 2 to Python 3 - (2016-10-30)

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All the pieces fall into place - hotel and courses
Some other Articles
What have iTime, honeytrapagency and domain listing center got in common?
Refactoring - a PHP demo becomes a production page
Which country does a search engine think you are located in?
All the pieces fall into place - hotel and courses
The road ahead - Python 3
Sharing variables with functions, but keeping them local too - Python
Looking for a value in a list - Python
Howto - write and manage a news box on your web page
Picturing the rain
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This is a page archived from The Horse's Mouth at http://www.wellho.net/horse/ - the diary and writings of Graham Ellis. Every attempt was made to provide current information at the time the page was written, but things do move forward in our business - new software releases, price changes, new techniques. Please check back via our main site for current courses, prices, versions, etc - any mention of a price in "The Horse's Mouth" cannot be taken as an offer to supply at that price.

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