[perl-python] 20050118 keyed list

[Xah Lee]

© # -*- coding: utf-8 -*-
©
© # in Python, there's a special type of
© # data structure called keyed list.  it
© # is a unordered list of pairs, each
© # consists of a key and a value. It is
© # also known as dictionary.
©
© # define a keyed list
© aa = {'john':3, 'mary':4, 'jane':5, 'vicky':7}
© print aa
©
© # getting value from a key
© print 'mary is', aa['mary']
©
© # delete an entry
© del aa['vicky']
© print aa
©
© # get just the keys
© print aa.keys()
©
© # check if a key exists
© print aa.has_key('mary')
©
© # to learn more,
© # type help() and DICTIONARIES
© # or see
© # http://python.org/doc/2.3.4/tut/node7.html
©
© -------------------------------------------
© # in perl, keyed-list is done like this:
©
© %a = ('john',3, 'mary', 4, 'jane', 5, 'vicky',7);
© use Data::Dumper qw(Dumper);
© print Dumper \%a;
©
© # the syntax of keyed list in Perl is too complex
© # to be covered in a short message.
© # see "perldoc perldata" for an unix-styled course.
©
©   Xah
©   xah at xahlee.org
©   http://xahlee.org/PageTwo_dir/more.html