diff options
Diffstat (limited to 'Lib/collections.py')
| -rw-r--r-- | Lib/collections.py | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/Lib/collections.py b/Lib/collections.py index 487b119..2a58b86 100644 --- a/Lib/collections.py +++ b/Lib/collections.py @@ -54,6 +54,7 @@ def namedtuple(typename, field_names, verbose=False): seen_names.add(name) # Create and fill-in the class template + numfields = len(field_names) argtxt = repr(field_names).replace("'", "")[1:-1] # tuple repr without parens or quotes reprtxt = ', '.join('%s=%%r' % name for name in field_names) dicttxt = ', '.join('%r: t[%d]' % (name, pos) for pos, name in enumerate(field_names)) @@ -63,7 +64,13 @@ def namedtuple(typename, field_names, verbose=False): _fields = %(field_names)r \n def __new__(cls, %(argtxt)s): return tuple.__new__(cls, (%(argtxt)s)) \n - _cast = classmethod(tuple.__new__) \n + @classmethod + def _make(cls, iterable): + 'Make a new %(typename)s object from a sequence or iterable' + result = tuple.__new__(cls, iterable) + if len(result) != %(numfields)d: + raise TypeError('Expected %(numfields)d arguments, got %%d' %% len(result)) + return result \n def __repr__(self): return '%(typename)s(%(reprtxt)s)' %% self \n def _asdict(t): @@ -71,7 +78,7 @@ def namedtuple(typename, field_names, verbose=False): return {%(dicttxt)s} \n def _replace(self, **kwds): 'Return a new %(typename)s object replacing specified fields with new values' - return self.__class__._cast(map(kwds.get, %(field_names)r, self)) \n\n''' % locals() + return self.__class__._make(map(kwds.get, %(field_names)r, self)) \n\n''' % locals() for i, name in enumerate(field_names): template += ' %s = property(itemgetter(%d))\n' % (name, i) if verbose: |