Pythonic way to find maximum value and its index in a list?

I think the accepted answer is great, but why don't you do it explicitly? I feel more people would understand your code, and that is in agreement with PEP 8:

max_value = max(my_list)
max_index = my_list.index(max_value)

This method is also about three times faster than the accepted answer:

import random
from datetime import datetime
import operator

def explicit(l):
    max_val = max(l)
    max_idx = l.index(max_val)
    return max_idx, max_val

def implicit(l):
    max_idx, max_val = max(enumerate(l), key=operator.itemgetter(1))
    return max_idx, max_val

if __name__ == "__main__":
    from timeit import Timer
    t = Timer("explicit(l)", "from __main__ import explicit, implicit; "
          "import random; import operator;"
          "l = [random.random() for _ in xrange(100)]")
    print "Explicit: %.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)

    t = Timer("implicit(l)", "from __main__ import explicit, implicit; "
          "import random; import operator;"
          "l = [random.random() for _ in xrange(100)]")
    print "Implicit: %.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)

Results as they run in my computer:

Explicit: 8.07 usec/pass
Implicit: 22.86 usec/pass

Other set:

Explicit: 6.80 usec/pass
Implicit: 19.01 usec/pass

There are many options, for example:

import operator
index, value = max(enumerate(my_list), key=operator.itemgetter(1))