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Sane · Feb 23rd, 2006, 5:31 PM

After noting the power of Arevos' cache function, I wanted to see how decorators worked.

I <3 Decorators, very handy for applying a common transformation easily to your functions. It's a useful thing to learn, and very easy to understand once you see its logic.

Here's one I made for my website

(Toggle Plain Text)

def serveError(func_name, func_code, func_error):
    return """<html>
<font face="courier new">
Server has encountered an error.<br />
<br />
      Error <i>%s</i><br />
In Function <b><i>%s</i></b><br />
         At <i>%s</i><br />
<br />
</font>
</html>"""%(func_error, func_name, func_code)



from sys import exc_info
def debug_wrapper(func):
    """If an error happens inside the function
    it will be caught and appropriately acted upon."""
    def new_func(*args):
        try:
            return func(*args)
        except:
            return serveError(func.func_name, func.func_code, exc_info()[0])
    return new_func




@debug_wrapper
def foo():
    raise KeyError


print foo()

Any function I put "@debug_wrapper" before, will now display something other then a CherryPy error.

Handy. Got any interesting ones?

Edit:

Here's Arevos' cache function:

(Toggle Plain Text)

def cached(func):
    """Creates a cached function.
    Cached function cannot handle keyword or mutable arguments."""
    store = {}
    def cached_func(*args):
        if not store.has_key(args):
            store[args] = func(*args)
        return store[args]
    return cached_func

@cached
def foo(x):
    return len(x)

print foo("Hello World!") # calculates and prints 12
print foo("Hello World!") # prints 12 without calculating

Feb 23rd, 2006, 5:31 PM	#1
Sane Programming Guru Join Date: Apr 2005 Location: Waterloo, Ontario Posts: 1,886 Rep Power: 5	<3 Decorators After noting the power of Arevos' cache function, I wanted to see how decorators worked. I <3 Decorators, very handy for applying a common transformation easily to your functions. It's a useful thing to learn, and very easy to understand once you see its logic. Here's one I made for my website (Toggle Plain Text) def serveError(func_name, func_code, func_error): return """<html> <font face="courier new"> Server has encountered an error.<br /> <br /> Error <i>%s</i><br /> In Function <b><i>%s</i></b><br /> At <i>%s</i><br /> <br /> </font> </html>"""%(func_error, func_name, func_code) from sys import exc_info def debug_wrapper(func): """If an error happens inside the function it will be caught and appropriately acted upon.""" def new_func(args): try: return func(args) except: return serveError(func.func_name, func.func_code, exc_info()[0]) return new_func @debug_wrapper def foo(): raise KeyError print foo() def serveError(func_name, func_code, func_error): return """<html> <font face="courier new"> Server has encountered an error.<br /> <br /> Error <i>%s</i><br /> In Function <b><i>%s</i></b><br /> At <i>%s</i><br /> <br /> </font> </html>"""%(func_error, func_name, func_code) from sys import exc_info def debug_wrapper(func): """If an error happens inside the function it will be caught and appropriately acted upon.""" def new_func(args): try: return func(args) except: return serveError(func.func_name, func.func_code, exc_info()[0]) return new_func @debug_wrapper def foo(): raise KeyError print foo() Any function I put "@debug_wrapper" before, will now display something other then a CherryPy error. Handy. Got any interesting ones? Edit: Here's Arevos' cache function: (Toggle Plain Text) def cached(func): """Creates a cached function. Cached function cannot handle keyword or mutable arguments.""" store = {} def cached_func(args): if not store.has_key(args): store[args] = func(args) return store[args] return cached_func @cached def foo(x): return len(x) print foo("Hello World!") # calculates and prints 12 print foo("Hello World!") # prints 12 without calculating def cached(func): """Creates a cached function. Cached function cannot handle keyword or mutable arguments.""" store = {} def cached_func(args): if not store.has_key(args): store[args] = func(args) return store[args] return cached_func @cached def foo(x): return len(x) print foo("Hello World!") # calculates and prints 12 print foo("Hello World!") # prints 12 without calculating

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