Re: Python .. replacing COBOL.



"Richard" <riplin@xxxxxxxxxxxx> wrote in message
news:facb1f14-7736-4df2-85df-27c1eac54eb1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Apr 28, 10:13 am, "Pete Dashwood"
<dashw...@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
"Richard" <rip...@xxxxxxxxxxxx> wrote in message

news:505bcb44-9b7c-4a26-b662-c3e08f6f24fb@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

From:

http://www.pythonthreads.com/news/latest/python-is-the-truly-object-o...

I was amused by this:

"""If we take a look at the top 10 programming languages, not much has
happened the last five years. Only Python entered the top 10,
replacing COBOL. """

This doesn't actuallysay that 'Python replaced COBOL', only that
COBOL dropped off the top 10 list and Python is now on it.

4 or 5 years ago 80% of my programming was still COBOL, now it is
about 80% Python.

From a cursory inspection carried out some time ago, I have to say that
Python looks more viable than Perl.

Some questions, Richard:

1. Are you undertaking actual application development in Python, as you
would have in COBOL? (I thought it was more for scripting...for me, that
would be "gluing" components together, rather than actually building
components with it.)

Most of what I do in Python is 'middleware'. Though I just did an
order system frontend to a COBOL accounting system. It uses Glade for
the UI and SQLite for the database and runs on Nokia N800 tablets
(pocket sized), ASUS eee, Linux, and Windows with no code changes. To
run stand alone for the reps in the field, who may be out of cell
phone area, it takes extracts from the main system and sends back the
orders that have been taken. It takes up 360Mbyte on the disk, but
most of that is the catalogue images it shows.

2. Can you write less of it than an equivalent in COBOL? (Does it save on
code lines?)

Everything is less than COBOL. One can do in a few lines what would
take pages in COBOL, or even in C.

I tend to write stuff that is table driven, even in Cobol, but with
Python it tends to be configuration file driven. For example the
config file contains a description of the extract file from the Cobol
system, including a name, type and size, and a list of the fields
required to be stored in the SQLite. The program automatically creates
and updates the tables without any line of code having the name of a
field, it builds the SQL code in flight.

The UI has field names based on the names used in the SQL tables. So I
can take DB rows and cycle through the fields looking for a match to
set the UI. A dozen or two lines will populate an enquirey screen.
Change the screen layout in Glade, no change required in code.

for (name,...) in dbrownames:
if ( window has 'o' + name ):
data = dbrow[name]
(type, size, formt, ..) = fieldDictionary[name]
if ( type = 'X' ):
windowfield.setText(data)
elif (type = 'N' ):
format ...
...

Of course it does need to know about price, discount and quantity
stuff, but mostly the program is ignorant about the data fields and
has no reference to them outside the tables and dictionaries created
from the configuration files.

3. Do you have a full IDE for it, like Eclipse or VS?

You can use those, but I don't like IDEs, I never found one that
worked the way that _I_ wanted. I use Midnight Commander, Setedit and
make files.

[Pete]

Thanks very much for that, it looks most impressive :-)

I've been using templates for a long time also, and the Stimulsoft package
uses Dictionary fields that provide a separation layer from the actual
program code.

Although I have a soft spot for COBOL, when tools like you describe are
available, it's really not much of a contest.

I think your "Glade" is probably very similar to the Stimulsoft Report
Designer - provides a visual layout and manipulation that has no impact on
program code. It is a report object, and as such, is encapsulated. It just
consumes a dataset provided to it.

I'm really enjoying doing these reports now... wish I'd had this stuff years
ago :-)

Pete.
--
"I used to write COBOL...now I can do anything."




.

Relevant Pages

  • Re: Cross-language challenge (of POSSIBLE interest)
    ... with doing this in Cobol yet. ... Python is an interpreted scripting language. ... Adding writing to an ISAM makes it 12. ... ie no counting occurances. ...
    (comp.lang.cobol)
  • Re: How to read files written with COBOL
    ... Batista, Facundo wrote: ... > I'm trying to convert my father from using COBOL to Python,:) ... and fixed point formats. ...
    (comp.lang.python)
  • Re: Python .. replacing COBOL.
    ... COBOL dropped off the top 10 list and Python is now on it. ... Python it tends to be configuration file driven. ... it builds the SQL code in flight. ...
    (comp.lang.cobol)
  • Re: compile+link Fujitsu Linux
    ... The Cobol standard has supported pointers for six years, ... It is common for most of a large business application to be written in Cobol, ... You don't know Python then. ... chosen the compiler options and link parameters that work best for me. ...
    (comp.lang.cobol)
  • Re: How to read files written with COBOL
    ... >> It should avoid us the work to write a COBOL program that open the COBOL ... >> Facundo Batista ... > asked about python to legacy mvs particularly for DB2 and Adabas access. ...
    (comp.lang.python)