test Perl 6 code in python page

Part of #1387

Author: coke

doc/Language/py-nutshell.pod6

@@ -19,10 +19,12 @@ optional.  A return is added to the end of the line.
 
 Python 2
 
+=for code :lang<python>
     print "Hello, world!"
 
 Python 3
 
+=for code :lang<python>
     print("Hello, world!")
 
 Perl 6
@@ -34,6 +36,7 @@ the C<gist> method of its argument.
 
 Perl 6
 
+   my $hello; ...;
    say "Hello, world!";  # also prints "Hello, world"
    say $hello;           # same as: put $hello.gist
 
@@ -66,6 +69,7 @@ is a closing curly brace followed by a newline.
 
 Python
 
+=for code :lang<python>
     print 1 + 2 + \
         3 + 4
     print ( 1 +
@@ -84,6 +88,7 @@ uses curly braces.
 
 Python
 
+=for code :lang<python>
     if 1 == 2:
         print "Wait, what?"
     else:
@@ -104,6 +109,7 @@ conditionals, as shown above.
 
 In Python, variables are declared and initialized at the same time:
 
+=for code :lang<python>
     foo = 12
     bar = 19
 
@@ -122,6 +128,7 @@ Immutable variables can be sigil-less, if they are declared with a C<\>.
 
 Python
 
+=begin code :lang<python>
     s = 10
     l = [1, 2, 3]
     d = { a : 12, b : 99 }
@@ -130,6 +137,7 @@ Python
     print l[2]
     print d['a']
     # 10, 2, 12
+=end
 
 Perl 6
 
@@ -155,6 +163,7 @@ In Perl 6, every block creates a lexical scope.
 
 Python
 
+=for code :lang<python>
     if True:
         x = 10
     print x
@@ -177,6 +186,7 @@ Perl 6
 
 Python
 
+=for code :lang<python>
    x = 10
    for x in 1, 2, 3:
        pass
@@ -196,6 +206,7 @@ Lambdas in Python can be written as blocks or pointy blocks in Perl 6.
 
 Python
 
+=for code :lang<python>
     l = lambda i: i + 12
 
 Perl 6
@@ -218,6 +229,7 @@ Another example (from the Python L<FAQ|https://docs.python.org/3/faq/programming
 
 Python
 
+=for code :lang<python>
     squares = []
     for x in range(5):
         squares.append(lambda: x ** 2)
@@ -253,6 +265,7 @@ or symbol that can be used in Perl 6 has an ASCII equivalent
 
 Python has C<for> loops and C<while> loops:
 
+=for code :lang<python>
     for i in 1, 2:
         print i
     j = 1
@@ -282,6 +295,7 @@ in Perl 6.
 
 Python
 
+=for code :lang<python>
     for i in range(10):
         if i == 3:
             continue
@@ -306,12 +320,14 @@ in Perl 6.  These both print 1, 2, 3.
 
 Python
 
+=begin code :lang<python>
     def count():
         for i in 1, 2, 3:
             yield i
 
     for c in count():
         print c
+=end code
 
 Perl 6
 
@@ -333,24 +349,30 @@ Perl 6
 Declaring a function (subroutine) with C<def> in Python is accomplished
 with C<sub> in Perl 6.
 
+=begin code :lang<python>
     def add(a, b):
         return a + b
 
     sub add(\a, \b) {
         return a + b
     }
+=end code
 
 The C<return> is optional; the value of the last expression is used as
 the return value:
 
+=begin code
     sub add(\a, \b) {
         a + b
     }
+=end code
 
+=begin code
     # using variables with sigils
     sub add($a, $b) {
         $a + $b
     }
+=end code
 
 Python 2 functions can be called with positional arguments
 or keyword arguments.  These are determined by the caller.
@@ -360,11 +382,13 @@ by the signature of the routine.
 
 Python
 
+=begin code :lang<python>
     def speak(word, times):
         for i in range(times):
             print word
     speak('hi', 2)
     speak(word='hi', times=2)
+=end code
 
 Perl 6
 
@@ -397,6 +421,7 @@ could be made available by declaring a routine as a C<multi>.
 
 Named parameters can be sent using a variety of formats:
 
+    sub hello {...};
     # all the same
     hello(name => 'world'); # fat arrow syntax
     hello(:name('world'));  # pair constructor
@@ -409,27 +434,29 @@ a pointy block.
 
 Python
 
+=for code :lang<python>
     square = lambda x: x ** 2
 
 Perl 6
 
-    $square = sub ($x) { $x ** 2 };  # anonymous sub
-    $square = -> $x { $x ** 2 };     # pointy block
-    $square = { $^x ** 2 };          # placeholder variable
-    $square = { $_ ** 2 };           # topic variable
+    my $square = sub ($x) { $x ** 2 };  # anonymous sub
+    my $square = -> $x { $x ** 2 };     # pointy block
+    my $square = { $^x ** 2 };          # placeholder variable
+    my $square = { $_ ** 2 };           # topic variable
 
 Placeholder variables are lexicographically ordered to form positional parameters.
 i.e. these are the same:
 
-    $power = { $^x ** $^y }
-    $power = -> $x, $y { $x ** $y }
+    my $power = { $^x ** $^y };
+    my $power = -> $x, $y { $x ** $y };
 
 =head2 List Comprehensions
 
 Postfix modifiers and anonymous functions can be combined to make list comprehensions.
 
 Python
 
+=for code :lang<python>
     [ i * 2 for i in 3, 9 ]
 
 Perl 6
@@ -441,6 +468,7 @@ Perl 6
 Conditionals can be applied, but the C<if> comes first,
 unlike in Python where the if comes second.
 
+=for code :lang<python>
     [ x * 2 for x in 1, 2, 3 if x > 1 ]
 
 vs
@@ -450,6 +478,7 @@ vs
 For nested loops, the cross product operator C<X>
 will help:
 
+=for code :lang<python>
     [ i + j for i in 3,9 for j in 2,10 ]
 
 becomes either of these:
@@ -467,6 +496,7 @@ First, "instance variables", aka attributes in Perl 6:
 
 Python:
 
+=for code :lang<python>
     class Dog:
         def __init__(self, name):
             self.name = name
@@ -482,13 +512,15 @@ and use the method C<new>.
 
 Python
 
+=for code :lang<python>
     d = Dog('Fido')
     e = Dog('Buddy')
     print d.name
     print e.name
 
 Perl 6
 
+    class Dog {}; ...;
     my $d = Dog.new(:name<Fido>);
     my $e = Dog.new(:name<Buddy>);
     say $d.name;
@@ -499,6 +531,7 @@ is to just declare a lexical variable and a method for accessing it.
 
 Python:
 
+=for code :lang<python>
     class Dog:
         kind = 'canine'                # class attribute
         def __init__(self, name):
@@ -529,6 +562,7 @@ To mutate attributes, in Perl 6 you"ll want to use C<is rw>:
 
 Python:
 
+=for code :lang<python>
     class Dog:
         def __init__(self, name):
             self.name = name
@@ -547,6 +581,7 @@ Inheritance is done using C<is>:
 
 Python
 
+=begin code :lang<python>
     class Animal:
         def jump(self):
             print ("I am jumping")
@@ -556,6 +591,7 @@ Python
 
     d = Dog()
     d.jump()
+=end code
 
 Perl 6
 
@@ -575,15 +611,20 @@ Multiple inheritance is possible by using C<is> multiple times, or with C<also>.
 
 Python
 
+=for code :lang<python>
     class Dog(Animal, Friend, Pet):
         pass
 
 Perl 6
 
-    class Dog is Animal is Friend is Pet { ... }
+    class Animal {}; class Friend {}; class Pet {};
+    ...;
+    class Dog is Animal is Friend is Pet {};
 
 or
 
+    class Animal {}; class Friend {}; class Pet {};
+    ...;
     class Dog is Animal {
         also is Friend;
         also is Pet;
@@ -599,6 +640,7 @@ in another one.  In Perl 6, this is done with C<wrap>.
 
 Python
 
+=begin code :lang<python>
     def greeter(f):
         def new():
             print 'hello'
@@ -610,6 +652,7 @@ Python
         print 'world'
 
     world();
+=end code
 
 Perl 6
 
@@ -650,6 +693,7 @@ or exiting a scope.
 Here's a python context manager that prints the strings
 'hello', 'world', and 'bye':
 
+=begin code :lang<python>
     class hello:
         def __exit__(self, type, value, traceback):
             print 'bye'
@@ -658,6 +702,7 @@ Here's a python context manager that prints the strings
 
     with hello():
         print 'world'
+=end code
 
 For enter and exit events, passing a block as
 an argument would be one option:
@@ -687,5 +732,4 @@ X<|input (Python)>
 
 See the L<prompt> function.
 
-
 =end pod

xt/examples-compilation.t

@@ -31,7 +31,6 @@ if @*ARGS {
             doc/Language/modules.pod6
             doc/Language/phasers.pod6
             doc/Language/pod.pod6
-            doc/Language/py-nutshell.pod6
             doc/Language/tables.pod6
          >);
         push @files, $file;