Adds examples of function calling conventions.

Author: paulross

Beginers/ExampleFunctions/A_functions_simple.py

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+#!/usr/bin/env python
+"""Examples of Python functions.
+
+Created on Aug 25, 2011
+
+@author: paulross
+"""
+
+###################
+# Simple functions.
+###################
+def noArgs():
+    """Function that takes no arguments."""
+    print '    noArgs(): No arguments'
+
+def twoArgs(a, b):
+    """Function that takes two arguments."""
+    print '    twoArgs(): a=%s, b=%s' % (a, b)
+
+def main():
+    print 'callSimple():'
+    noArgs()
+    twoArgs(12, 34)
+    twoArgs(b='b_given', a='a_given')
+
+if __name__ == '__main__':
+    main()
+########################
+# END: Simple functions.
+########################

Beginers/ExampleFunctions/B_functions_default.py

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+#!/usr/bin/env python
+"""Does...
+
+Created on Aug 25, 2011
+
+@author: paulross
+"""
+
+__author__  = 'Paul Ross'
+__date__    = '2011-08-03'
+__version__ = '0.1.0'
+__rights__  = 'Copyright (c) 2011 Paul Ross.'
+
+
+##################################
+# Simple functions, with defaults.
+##################################
+def twoArgsOneDefault(a, b='default_value'):
+    print '    a=%s, b=%s' % (a, b)
+    
+def main():
+    print 'callTwoArgsOneDefault():'
+    twoArgsOneDefault('a_only')
+    twoArgsOneDefault('a_value', b='b_given')
+
+if __name__ == '__main__':
+    main()
+
+## Having positional arguments after a default is a syntax error
+#def twoArgsOneDefaultWrong(a='something', b):
+#    print 'a=%s, b=%s' % (a, b)
+
+#######################################
+# END: Simple functions, with defaults.
+#######################################

Beginers/ExampleFunctions/C_functions_default_mutable.py

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+#!/usr/bin/env python
+"""Does...
+
+Created on Aug 25, 2011
+
+@author: paulross
+"""
+
+__author__  = 'Paul Ross'
+__date__    = '2011-08-03'
+__version__ = '0.1.0'
+__rights__  = 'Copyright (c) 2011 Paul Ross.'
+
+################################
+# Problem with mutable defaults.
+################################
+def defaultMutableCatch(a=[1,]):
+    a.append('Ooops')
+    return a
+
+x = [1,]
+
+def defaultMutableFix(a=x):
+    if a is None:
+        a = []
+    a.append('Ooops')
+    return a
+
+def main():
+    # defaultMutableCatch()
+    print 'defaultMutableCatch():', defaultMutableCatch()
+    print 'defaultMutableCatch():', defaultMutableCatch([])
+    print 'defaultMutableCatch():', defaultMutableCatch()
+    # defaultMutableFix()
+    print 'defaultMutableFix():', defaultMutableFix()
+    print 'defaultMutableFix():', defaultMutableFix()
+    print 'defaultMutableFix():', defaultMutableFix()
+    
+if __name__ == '__main__':
+    main()
+#####################################
+# END: Problem with mutable defaults.
+#####################################

Beginers/ExampleFunctions/D_functions_parrot.py

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+#!/usr/bin/env python
+"""Does...
+
+Created on Aug 25, 2011
+
+@author: paulross
+"""
+
+__author__  = 'Paul Ross'
+__date__    = '2011-08-03'
+__version__ = '0.1.0'
+__rights__  = 'Copyright (c) 2011 Paul Ross.'
+
+###################################
+# The many ways of calling parrot()
+###################################
+def parrot(voltage,
+           state='a stiff',
+           action='voom',
+           type='Norwegian Blue'):
+    print "-- This parrot wouldn't", action,
+    print "if you put", voltage, "volts through it."
+    print "-- Lovely plumage, the", type
+    print "-- It's", state, "!"
+
+def main():
+    parrot(1000)
+    print
+    parrot(action='VOOOOOM', voltage=1000000)
+    print
+    parrot('a thousand', state='pushing up the daisies')
+    print
+    parrot('a million', 'bereft of life', 'jump')
+    print
+    # These will raise a SyntaxError
+#    parrot()                     # required argument missing
+#    parrot(voltage=5.0, 'dead')  # non-keyword argument following keyword
+    parrot(110, 'a', 'b', voltage=220)     # duplicate value for argument
+#    parrot(actor='John Cleese')  # unknown keyword
+
+if __name__ == '__main__':
+    main()
+    
+########################################
+# END: The many ways of calling parrot()
+########################################

Beginers/ExampleFunctions/E_functions_cheeseshop.py

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+#!/usr/bin/env python
+"""Does...
+
+Created on Aug 25, 2011
+
+@author: paulross
+"""
+
+__author__  = 'Paul Ross'
+__date__    = '2011-08-03'
+__version__ = '0.1.0'
+__rights__  = 'Copyright (c) 2011 Paul Ross.'
+
+import pprint
+
+#########################
+# With keyword arguments.
+#########################
+def cheeseshop(kind, *args, **kwargs):
+    print "-- Do you have any", kind, "?"
+    print " *args ".center(40, '-')
+    pprint.pprint(args)
+    print " *args ".center(40, '-')
+    print " *kwargs ".center(40, '-')
+    pprint.pprint(kwargs)
+    print " *kwargs ".center(40, '-')
+
+def main():
+    cheeseshop(
+        "Limburger",
+#         "It's very runny, sir.",
+#         "It's really very, VERY runny, sir.",
+        shopkeeper='Michael Palin',
+        client="John Cleese",
+        sketch="Cheese Shop Sketch")
+    
+if __name__ == '__main__':
+    main()
+#########################
+# With keyword arguments.
+#########################

Beginers/ExampleFunctions/F_functions_unpack_args.py

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+#!/usr/bin/env python
+"""Illustrates Python function arguments packing and unpacking.
+
+Created on Aug 25, 2011
+
+@author: paulross
+"""
+
+def unpackArgs(*args):
+    for arg in args:
+        print type(arg), arg
+    print
+
+def main():
+    print 'callUnpackArgs():'
+    print 'Specific arguments:'
+    unpackArgs(0,1,2,3)
+    l = ['a', 'b', 'c', 'd']
+    print 'Single list argument:'
+    unpackArgs(l)
+    print 'Unpacked list argument:'
+    unpackArgs(*l)
+    print 'Single value unpacked'
+    unpackArgs(*'hello')
+
+if __name__ == '__main__':
+    main()

Beginers/ExampleFunctions/G_functions_unpack_kwargs.py

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+#!/usr/bin/env python
+"""Illustrates Python function keyword arguments packing and unpacking.
+
+Created on Aug 25, 2011
+
+@author: paulross
+"""
+
+def unpackKwargs(**kwargs):
+    keys = kwargs.keys()
+    keys.sort()
+    for kw in keys:
+        print kw, ":", kwargs[kw]
+
+def main():
+    print 'callUnpackKwargs():'
+    print 'Specific arguments:'
+    unpackKwargs(name='python', version=2.6)
+    d = {
+        'name' : 'python',
+        'version' : 2.6,
+    }
+    print
+    print 'Unpacked arguments:'
+    unpackKwargs(**d)
+
+if __name__ == '__main__':
+    main()