Feature suggestion -- return if true

Thu Apr 21 06:13:43 EDT 2011

Am 13.04.2011 01:06, schrieb Ethan Furman:
> --> def func():
> --> var1 = something()
> --> var2 = something_else('this')
> --> return? var1.hobgle(var2)
> --> var3 = last_resort(var1)
> --> return var3.wiglat(var2)

This makes me think of a decorator which can mimic the wantend behaviour:
def getfirst(f):
 from functools import wraps
 @wraps(f)
 def func(*a, **k):
 for i in f(*a, **k):
 if i: return i
 return func
# [BTW: a kind of "return decorator" would be nice here ;-)]
@getfirst
def func():
 var1 = something()
 var2 = something_else('this')
 yield var1.hobgle(var2)
 var3 = last_resort(var1)
 yield var3.wiglat(var2)
 yield "Even that did not work."
This has the advantage of being flexible about which condition to 
evaluate: maybe the func does return tuples of which only the 2nd part 
is relevant concerning the check. Then just do
def getfirst(f):
 from functools import wraps
 @wraps(f)
 def func(*a, **k):
 for i in f(*a, **k):
 if i[1]: return i
 return func
@getfirst
def func():
 var1 = something()
 var2 = something_else('this')
 yield "first try", var1.hobgle(var2)
 var3 = last_resort(var1)
 yield "second try", var3.wiglat(var2)
 yield "default value", "Even that did not work."
Disclaimer: Untested, but you should get the idea.
Thomas