Is there way to write following code in one line?
my_list = [[1, 1, 1], [1, 2], [1, 3]]
result = 1
for l in list:
result = result * sum(l)
Asked
Active
Viewed 780 times
1
micgeronimo
- 1,899
- 5
- 20
- 40
4 Answers
5
Use reduce on the summed sublists gotten from map.
This does it:
>>> from functools import reduce
>>> reduce(lambda x,y: x*y, map(sum, my_list))
36
In python 2.x, the import will not be needed as reduce is a builtin:
>>> reduce(lambda x,y: x*y, map(sum, my_list))
36
Moses Koledoye
- 74,909
- 8
- 119
- 129
-
Wouldn't it also work without the import? At least for me it does. – Ohumeronen Jul 18 '16 at 15:55
-
2@Ohumeronen not in Python 3. – vaultah Jul 18 '16 at 15:56
3
Here you go:
import operator
my_list = [[1, 1, 1], [1, 2], [1, 3]]
print reduce(operator.mul, [sum(l) for l in my_list])
Ohumeronen
- 1,517
- 2
- 11
- 22
0
with numpy
In [1]: from numpy import prod
In [2]: prod([sum(i) for i in my_list])
Out[2]: 36
Another method.
In [1]: eval('*'.join(str(item) for item in [sum(i) for i in my_list]))
Out[1]: 36
Rahul K P
- 10,793
- 3
- 32
- 47
-
1@micgeronimo It's also another attempt. And i showed another method also. – Rahul K P Jul 18 '16 at 16:21
0
Maybe there are some people out there who think that a one-liner which requires an import statement is not a true one-liner. Just for fun, those who think so might prefer this admittedly obfuscated solution to the approaches suggested so far:
In [389]: (lambda f: lambda n: f(f, n))(lambda rec, x: 1 if not x else x[0]*rec(rec, x[1:]))(map(sum, my_list))
Out[389]: 36
The code above relies on the built-in functions map() and sum() to compute the sums of the sublists, and on recursive calls to a lambda function to compute the product of the sums.
