NameError: name 'reduce' is not defined in Python

python reduce python-3.2
Sergey picture Sergey · Dec 31, 2011 · Viewed 127.7k times · Source

I'm using Python 3.2. Tried this:

xor = lambda x,y: (x+y)%2
l = reduce(xor, [1,2,3,4])

And got the following error:

l = reduce(xor, [1,2,3,4])
NameError: name 'reduce' is not defined

Tried printing reduce into interactive console - got this error:

NameError: name 'reduce' is not defined


Is reduce really removed in Python 3.2? If that's the case, what's the alternative?

Answer

Ignacio Vazquez-Abrams picture Ignacio Vazquez-Abrams · Dec 31, 2011

It was moved to functools.

Related questions

Finding the average of a list

I have to find the average of a list in Python. This is my code so far l = [15, 18, 2, 36, 12, 78, 5, 6, 9] print reduce(lambda x, y: x + y, l) I've got it so it adds together the values in the list, but I …

Read More
How to use filter, map, and reduce in Python 3

filter, map, and reduce work perfectly in Python 2. Here is an example: >>> def f(x): return x % 2 != 0 and x % 3 != 0 >>> filter(f, range(2, 25)) [5, 7, 11, 13, 17, 19, 23] >>> def cube(x): return x*x*x >>&…

Read More
What is the 'pythonic' equivalent to the 'fold' function from functional programming?

What is the most idiomatic way to achieve something like the following, in Haskell: foldl (+) 0 [1,2,3,4,5] --> 15 Or its equivalent in Ruby: [1,2,3,4,5].inject(0) {|m,x| m + x} #> 15 Obviously, Python provides the reduce function, which is an implementation of fold, …

Read More