This solution give possibility to check method param type, raise needed exception type, and also have good readability in the decorator definition.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 | def accepts(exception,**types):
def check_accepts(f):
assert len(types) == f.func_code.co_argcount, \
'accept number of arguments not equal with function number of arguments in "%s"' % f.func_name
def new_f(*args, **kwds):
for i,v in enumerate(args):
if types.has_key(f.func_code.co_varnames[i]) and \
not isinstance(v, types[f.func_code.co_varnames[i]]):
raise exception("arg '%s'=%r does not match %s" % \
(f.func_code.co_varnames[i],v,types[f.func_code.co_varnames[i]]))
del types[f.func_code.co_varnames[i]]
for k,v in kwds.iteritems():
if types.has_key(k) and not isinstance(v, types[k]):
raise exception("arg '%s'=%r does not match %s" % \
(k,v,types[k]))
return f(*args, **kwds)
new_f.func_name = f.func_name
return new_f
return check_accepts
def exmaple():
@accepts(Exception,a=int,b=list,c=(str,unicode))
def test(a,b=None,c=None)
print 'ok'
test(13,c=[],b='df')
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