Python List Sorting

Question

my_list=raw_input('Please enter a list of items (separated by comma): ')
my_list=my_list.split()
my_list.sort()

print "List statistics: "

for x in my_list:
    z=my_list.count(x)

    if z>1:  
        print x, "is repeated", z, "time."
    else:
        print x, "is repeated", z, "times."

I am trying to get the program to sort the list alphabetically, then print how many of each it found. The output is:

List statistics: 
bird, is repeated 1 time.
cat, is repeated 1 time.
dog is repeated 1 time.
dog, is repeated 2 times.
dog, is repeated 2 times.

I only need it to print one time each. Also, I am trying to figure out how to put the item in quotation marks.

str.split with no argument splits on whitespace, not commas. — chepner
– chepner, Commented Sep 16, 2013 at 18:23

Joran Beasley · Accepted Answer · 2013-09-16 18:47:00Z

3

from itertools import Counter
my_list=raw_input('Please enter a list of items (separated by comma): ')
my_list=my_list.split(",")


print "List statistics: "
import operator
for item,count in sorted(Counter(my_list).items(),key =operator.itemgetter(0)) :

    if z==1:  
        print  '"%s" is repeated %d time.'%(item,count)
    else:
        print  '"%s" is repeated %d times.'%(item,count)

if you are using python < 2.7 you can make your own counter method

def Counter(a_list):
    d = {}
    for item in a_list:
        if d.get(item,None) is None:
           d[item] = 0
        d[item] += 1
    return d

edited Sep 16, 2013 at 18:47

answered Sep 16, 2013 at 17:18

Joran Beasley

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3 Comments

Abhijit Over a year ago

-1: OP mentioned that I am trying to get the program to sort the list alphabetically. I wonder, using COunter, how can you print it in alphabetic order. Also your program has lot of syntax errors.

Matthias Over a year ago

Using split() on a string with comma separated items will lead to wrong results.

Joran Beasley Over a year ago

I just copied and pasted his code for the split ... i just added the counter part ... anyway fixed the split and the alphabetical thing ...

Rohit Jain · Accepted Answer · 2013-09-16 17:15:26Z

1

You can iterate over a set created from list:

for x in set(my_list):
    z = my_list.count(x)

this way, you will only get each element once in the loop.

answered Sep 16, 2013 at 17:15

Rohit Jain

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Comments

Bleeding Fingers · Accepted Answer · 2013-09-16 18:01:48Z

0

Replace for x in my_list: with for x in sorted(list(set(my_list))):

And though not asked in the question you could use this:

print x, "is repeated", z, "time%s." %("s" if z > 1 else "")

instead of:

if z>1:  
    print x, "is repeated", z, "time."
else:
    print x, "is repeated", z, "times."

"Pythonic" as they call it.

edited Sep 16, 2013 at 18:01

answered Sep 16, 2013 at 17:16

Bleeding Fingers

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2 Comments

user2784808 Over a year ago

When I add that second line it only prints one of the items in the list such as "dog", but it will not print for all of the variables bird, cat, dog. Thanks for the help!

Bleeding Fingers Over a year ago

@user2784808 did you add it within the loop? indentations checked? btw answer updated.

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