2. equals( , ) Cross-platform, open-source, scripting language, multi-paradigm, dynamic typing, statement ratio: 6 There should be one way There’s more than one way Guido van Rossum Larry Wall 1991 1987 Python Perl Easy Difficult
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5. you must be joking! http://www.strombergers.com/python/ my @list = ('a', 'b', 'c'); my %hash; $hash{‘letters'} = list; print "@{$hash{‘letters'}}"; list = ['a', 'b', 'c'] hash = {} hash[‘letters'] = list print hash[‘letters'] package Person; use strict; sub new { my $class = shift; my $age = shift or die "Must pass age"; my $rSelf = {'age' => $age}; bless ($rSelf, $class); return $rSelf; } class Person: def __init__(self, age): self.age = age @list = ( [‘a’, ’b’, ’c’], [1, 2, 3] ); print “@{$list[0]}”; list = [ [‘a’, ’b’, ’c’], [1, 2, 3] ] print list[0]
6. More Perl bashing… http://www.strombergers.com/python/ sub add { $_[0] + $_[1]; } def add(a, b): return a + b sub add { my ($a, $b) = _@; return $a + $b; } sub add { my $a = shift; my $b = shift; return $a + $b; } def diff(a, b): return len(a) - len(b) sub diff { my ($aref, $bref) = _@; my (@a) = @$aref; my (@b) = @$bref; return scalar(@a) + scalar(@b); } sub add($, $) { local ($a, $b) = _@; return $a + $b; }
10. one of ten Perl myths http://www.perl.com/pub/a/2000/01/10PerlMyths.html “… Perl works the way you do…” “… That's one, fairly natural way to think about it…” while (<>) { s/(.*):(.*)/$2:$1/; print; } Swap two sections of a string: “aaa:bbb” -> “bbb:aaa” for line in file: line = line.strip() first, second = line.split(‘:’) print second+’:’+first while (<>) { chomp; ($first, $second) = split /:/; print $second, ":", $first, ""; } “… we can happily consign the idea that ‘Perl is hard’ to mythology.” from re import sub for line in file: print sub(‘(.*):(.*)’, r’:’, line)
