Looping over elements of named tuple in python

Question

I have a named tuple which I assign values to like this:

class test(object):             self.CFTs = collections.namedtuple('CFTs', 'c4annual c4perren c3perren ntfixing')              self.CFTs.c4annual = numpy.zeros(shape=(self.yshape, self.xshape))             self.CFTs.c4perren = numpy.zeros(shape=(self.yshape, self.xshape))             self.CFTs.c3perren = numpy.zeros(shape=(self.yshape, self.xshape))             self.CFTs.ntfixing = numpy.zeros(shape=(self.yshape, self.xshape)) 

Is there a way to loop over elements of named tuple? I tried doing this, but does not work:

for fld in self.CFTs._fields:                 self.CFTs.fld= numpy.zeros(shape=(self.yshape, self.xshape)) 

Answer 1

namedtuple is a tuple so you can iterate as over normal tuple:

>>> from collections import namedtuple >>> A = namedtuple('A', ['a', 'b']) >>> for i in A(1,2):     print i   1 2 

but tuples are immutable so you cannot change the value

if you need the name of the field you can use:

>>> a = A(1, 2) >>> for name, value in a._asdict().iteritems():     print name     print value   a 1 b 2  >>> for fld in a._fields:     print fld     print getattr(a, fld)   a 1 b 2 

Answer 2

from collections import namedtuple point = namedtuple('Point', ['x', 'y'])(1,2) for k, v in zip(point._fields, point):     print(k, v) 

Output:

x 1 y 2