How would you find how many times a number is entered?

[Thekid]

I'm wondering how you'd enter a lot of numbers and have the script print out the ones that were repeated the most. Something like this:

(numbers entered)
1,4,10,23,4,6,14,33,6,12,24,34,1,3,6,23,8,19,20,23
Print out would be:
1,4,6,23
because they are the most used, if I wanted only the highest 4 numbers used.

[bartonc]

I'm wondering how you'd enter a lot of numbers and have the script print out the ones that were repeated the most. Something like this:

(numbers entered)
1,4,10,23,4,6,14,33,6,12,24,34,1,3,6,23,8,19,20,23
Print out would be:
1,4,6,23
because they are the most used, if I wanted only the highest 4 numbers used.

l = [1,4,10,23,4,6,14,33,6,12,24,34,1,3,6,23,8,19,20,23]
l.sort()
outList = [] # an empty list
print l
itemCount = 1 # init the number if times this is in the list
for i, item in enumerate(l):
    try:
        j = l.index(item, i + 1) # don't actully need j
        itemCount += 1
    except ValueError:
        result = (itemCount, item)
        print result
        outList.append(result)
        itemCount = 1 # reset the number if times this is in the list
outList.sort(reverse=True)
for outTuple in outList[:4]:
    print outTuple[1],
 

Output:
[1, 1, 3, 4, 4, 6, 6, 6, 8, 10, 12, 14, 19, 20, 23, 23, 23, 24, 33, 34]
(2, 1)
(1, 3)
(2, 4)
(3, 6)
(1, 8)
(1, 10)
(1, 12)
(1, 14)
(1, 19)
(1, 20)
(3, 23)
(1, 24)
(1, 33)
(1, 34)
23 6 4 1

[Thekid]

Wow! Impressive.....thank you very much!

[bartonc]

Wow! Impressive.....thank you very much!

You're welcome. It's just a little something that I whipped up while eating my lunch.

[ghostdog74]

another way

>>> l = [1,4,10,23,4,6,14,33,6,12,24,34,1,3,6,23,8,19,20,23  ]
>>> cnt = [l.count(item) for item in set(l)]
>>> cnt
[2, 1, 1, 2, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1]
>>> sorted(zip(cnt,set(l)))[-4:]
[(2, 1), (2, 4), (3, 6), (3, 23)]
>>> for i in sorted(zip(cnt,set(l)))[-4:]:
...  print i[1],
...
1 4 6 23
 

[bvdet]

May I get in on this thread?

nums = [1,4,10,23,4,6,14,33,6,12,24,34,1,3,6,23,8,19,20,23]
def top_list(items, top):
    dd = {}
    for item in items:
        if item in dd:
            dd[item]=dd[item]+1
        else:
            dd[item]=1
    itemLst = [(dd[key],key) for key in dd]
    itemLst.sort(lambda a, b: cmp(b, a))
    print itemLst
    for i in range(min(top, len(itemLst))):
        yield itemLst[i][1]
 
for i in top_list(nums, 4):
    print i,
 
'''    
>>>  [(3, 23), (3, 6), (2, 4), (2, 1), (1, 34), (1, 33), (1, 24), (1, 20), (1, 19), (1, 14), (1, 12), (1, 10), (1, 8), (1, 3)]
23 6 4 1
'''

I am in Python 2.3, therefore the cmp function in sort.

[bartonc]

Thanks BV and GD. Two great coders show that there are alway many ways to skin a cat in Python. You guys rock!

[bartonc]

another way

>>> l = [1,4,10,23,4,6,14,33,6,12,24,34,1,3,6,23,8,19,20,23  ]
>>> cnt = [l.count(item) for item in set(l)]
>>> cnt
[2, 1, 1, 2, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1]
>>> sorted(zip(cnt,set(l)))[-4:]
[(2, 1), (2, 4), (3, 6), (3, 23)]
>>> for i in sorted(zip(cnt,set(l)))[-4:]:
...  print i[1],
...
1 4 6 23
 

I should have thought of pulling off the end of the list. Very nice.

[Thekid]

All very nice! Question though about ghostdog74's.....I get this:

Traceback (most recent call last):
File "<pyshell#8>", line 2, in <module>
print i[l],
TypeError: tuple indices must be integers

If I change it to simply 'print i' it works but like this:
(2, 1)
(2, 4)
(3, 6)
(2, 23)

This is fine but I was just curious as to why mine wouldn't print out the same way.

[bartonc]

All very nice! Question though about ghostdog74's.....I get this:

Traceback (most recent call last):
File "<pyshell#8>", line 2, in <module>
print i[l],
TypeError: tuple indices must be integers

If I change it to simply 'print i' it works but like this:
(2, 1)
(2, 4)
(3, 6)
(2, 23)

This is fine but I was just curious as to why mine wouldn't print out the same way.

... print i[1],

One is definitely an integer. You haven't included your version. Looks like you have a typo.

[ghostdog74]

All very nice! Question though about ghostdog74's.....I get this:

Traceback (most recent call last):
File "<pyshell#8>", line 2, in <module>
print i[l],
TypeError: tuple indices must be integers

If I change it to simply 'print i' it works but like this:
(2, 1)
(2, 4)
(3, 6)
(2, 23)

This is fine but I was just curious as to why mine wouldn't print out the same way.

as barton said, its a 1, not an 'l' . As you can see the results are tuples.