searching a namedtuple like a dictionary
namedtuple, python, search
Solution
I think you can use `getattr` to see if the field exists and either raise an exception or return a default value if it doesn't.
For example, based on the namedtuple documentation:
from collections import namedtuple
Point = namedtuple('Point', ['x', 'y'])
# An instance of the namedtuple
p = Point(1, 2)
In [1]: getattr(p, "x")
Out[1]: 1
In [2]: getattr(p, "z")
...
AttributeError: 'Point' object has no attribute 'z'
In [3]: getattr(f, "z", None)
Out[3]: None
Problem
to conserve memory & avoid redundant DB storage (yes possibly pre-optimizing), I'm using namedtuple instead of dictionary. But I need to search the collection of recs and my dictionary approach is: ``` import operator def query(D,key,val, keynotfound=None): ''' D: a list of dictionaries (but I want it to be namedtuples) key: the key to query val: the value to search for keynotfound: value if key is not found Returns elements in D such that operator(D.get(key,None), val) is true ''' op = operator.eq def try_op(f,x,y): try: return f(x,y) except Exception, exc: return False return (x for x in D if try_op(op, x.get(key,keynotfound),val)) ``` not working on namedtuple Any tips on how to subclass namedtuple to make it searchable like a dict? And not every instance will contain the same key/fields as the query-key so I need to skip that row rather than throw a key/attr error..