"""http://ginstrom.com/scribbles/2007/10/08/design-patterns-python-style/""" """An example of the Template pattern in Python""" ingredients = "spam eggs apple" line = '-' * 10 # Skeletons def iter_elements(getter, action): """Template skeleton that iterates items""" for element in getter(): action(element) print(line) def rev_elements(getter, action): """Template skeleton that iterates items in reverse order""" for element in getter()[::-1]: action(element) print(line) # Getters def get_list(): return ingredients.split() def get_lists(): return [list(x) for x in ingredients.split()] # Actions def print_item(item): print(item) def reverse_item(item): print(item[::-1]) # Makes templates def make_template(skeleton, getter, action): """Instantiate a template method with getter and action""" def template(): skeleton(getter, action) return template # Create our template functions templates = [make_template(s, g, a) for g in (get_list, get_lists) for a in (print_item, reverse_item) for s in (iter_elements, rev_elements)] # Execute them for template in templates: template()
点击run it 运行之!!!