Finding minimum value in list of lists

Question

I want to find the smallest value in a list of lists in Python. Example:

ls = [[2,3,5],[8,1,10]]

The minimum value in ls is 1. How can I get that in a simple way?

What did you try so far? Please read https://stackoverflow.com/help/minimal-reproducible-example — RafazZ, Jun 28 '19 at 18:00
The proposed dupe ([Optimise a minimum operation on a python list of list](https://stackoverflow.com/q/56668205/1782792)) had very little to do with this question. — jdehesa, Jun 28 '19 at 18:10
@cs95 Ah sorry I didn't see that, sure do close it if you found a proper dupe (I couldn't find it myself). That's a more general case, but if it's good for you it is for me. — jdehesa, Jun 28 '19 at 18:26
@jdehesa it isn't a perfect dupe, just a little more general. I'll go ahead and close it again. — cs95, Jun 28 '19 at 18:29

cs95 · Accepted Answer · 2019-06-30T15:01:29.140

4

# find the min of each sublist, then find the global min
min(map(min, ls))
# 1

# flatten `ls`, then find the min
min(y for x in ls for y in x)
# 1

# use itertools.chain to flatten `ls`
min(itertools.chain.from_iterable(ls))
# 1

ls = [[2, 3, 5], [8, 1, 10]] * 10000

%timeit min(y for x in ls for y in x)            # 7.31 ms ± 64.9 µs
%timeit min([min(l) for l in ls])                # 6.24 ms ± 56.9 µs
%timeit min(map(min, ls))                        # 5.44 ms ± 151 µs
%timeit min(min(ls, key=min))                    # 5.28 ms ± 129 µs
%timeit min(itertools.chain.from_iterable(ls))   # 2.67 ms ± 62.5 µs

edited Jun 30 '19 at 15:01

answered Jun 28 '19 at 18:01

cs95

379,657
97
704
746

There are dupes for it, but not for this exact question! – Devesh Kumar Singh Jun 28 '19 at 18:04
1

@DeveshKumarSingh Seems like an attempt at a self QA, so I posted what I thought were decent alternatives. – cs95 Jun 28 '19 at 18:05

score 1 · Answer 2 · answered Jun 28 '19 at 18:00

1

min_abs = min([min(l) for l in ls])

answered Jun 28 '19 at 18:00

lfvv

1,509
15
17

1

you can skip the `[` and `]`, and it avoid the temporary list. – jdehesa Jun 28 '19 at 18:01
Building a list of min values like this is a little more wasteful than it needs to be. See [here](https://stackoverflow.com/a/56811402/4909087) for a timings comparison. – cs95 Jun 30 '19 at 15:02

score 1 · Answer 3 · answered Jun 28 '19 at 18:05

1

You can simply try this:

res = min(min(ls, key=min))

answered Jun 28 '19 at 18:05

Anubhav Singh

8,321
4
25
43

Finding minimum value in list of lists

3 Answers3