Add __asdict__() to NamedTuple and refine the docs.
Add maxlen support to deque() and fixup docs.
Partially fix __reduce__(). The None as a third arg was no longer supported.
Still needs work on __reduce__() to handle recursive inputs.
diff --git a/Lib/collections.py b/Lib/collections.py
index 816f864..7b10712 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -18,19 +18,21 @@
(11, 22)
>>> p.x + p.y # fields also accessable by name
33
- >>> p # readable __repr__ with name=value style
+ >>> d = p.__asdict__() # convert to a dictionary
+ >>> d['x']
+ 11
+ >>> Point(**d) # convert from a dictionary
Point(x=11, y=22)
>>> p.__replace__('x', 100) # __replace__() is like str.replace() but targets a named field
Point(x=100, y=22)
- >>> d = dict(zip(p.__fields__, p)) # use __fields__ to make a dictionary
- >>> d['x']
- 11
"""
field_names = tuple(s.replace(',', ' ').split()) # names separated by spaces and/or commas
if not ''.join((typename,) + field_names).replace('_', '').isalnum():
raise ValueError('Type names and field names can only contain alphanumeric characters and underscores')
+ if any(name.startswith('__') and name.endswith('__') for name in field_names):
+ raise ValueError('Field names cannot start and end with double underscores')
argtxt = repr(field_names).replace("'", "")[1:-1] # tuple repr without parens or quotes
reprtxt = ', '.join('%s=%%r' % name for name in field_names)
template = '''class %(typename)s(tuple):
@@ -41,7 +43,10 @@
return tuple.__new__(cls, (%(argtxt)s))
def __repr__(self):
return '%(typename)s(%(reprtxt)s)' %% self
- def __replace__(self, field, value):
+ def __asdict__(self, dict=dict, zip=zip):
+ 'Return a new dict mapping field names to their values'
+ return dict(zip(%(field_names)r, self))
+ def __replace__(self, field, value, dict=dict, zip=zip):
'Return a new %(typename)s object replacing one field with a new value'
return %(typename)s(**dict(zip(%(field_names)r, self) + [(field, value)])) \n''' % locals()
for i, name in enumerate(field_names):