Issue 1818: collections.namedtuple() to support automatic renaming of invalid fieldnames.
diff --git a/Lib/collections.py b/Lib/collections.py
index 0fddb97..8d49cd5 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -16,7 +16,7 @@
### namedtuple
################################################################################
-def namedtuple(typename, field_names, verbose=False):
+def namedtuple(typename, field_names, verbose=False, rename=False):
"""Returns a new subclass of tuple with named fields.
>>> Point = namedtuple('Point', 'x y')
@@ -45,6 +45,16 @@
if isinstance(field_names, basestring):
field_names = field_names.replace(',', ' ').split() # names separated by whitespace and/or commas
field_names = tuple(map(str, field_names))
+ if rename:
+ names = list(field_names)
+ seen = set()
+ for i, name in enumerate(names):
+ if (not all(c.isalnum() or c=='_' for c in name) or _iskeyword(name)
+ or not name or name[0].isdigit() or name.startswith('_')
+ or name in seen):
+ names[i] = '_%d' % (i+1)
+ seen.add(name)
+ field_names = tuple(names)
for name in (typename,) + field_names:
if not all(c.isalnum() or c=='_' for c in name):
raise ValueError('Type names and field names can only contain alphanumeric characters and underscores: %r' % name)
@@ -54,7 +64,7 @@
raise ValueError('Type names and field names cannot start with a number: %r' % name)
seen_names = set()
for name in field_names:
- if name.startswith('_'):
+ if name.startswith('_') and not rename:
raise ValueError('Field names cannot start with an underscore: %r' % name)
if name in seen_names:
raise ValueError('Encountered duplicate field name: %r' % name)