Hi D'Arcy J.M. Cain, Thank you. I tried this and my list of 76,979 integers got reduced to a dictionary of 76,963 items, each item listing the integer value from the list, a comma, and a 1. I think what this is doing is finding all integers from my list that are unique (only one instance of it in the list), instead of creating a dictionary with integers that are not unique, with a count of how many times they occur. My dictionary should contain only 11 items listing 11 integer values and the number of times they appear in my original list.
Thanks, Paul J. Scipione GIS Database Administrator work: 602-371-7091 cell: 480-980-4721 -----Original Message----- From: D'Arcy J.M. Cain [mailto:da...@druid.net] Sent: Thursday, March 26, 2009 12:50 PM To: Scipione, Paul (ZP5296) Cc: python-list@python.org Subject: Re: Find duplicates in a list and count them ... On Thu, 26 Mar 2009 12:22:27 -0700 paul.scipi...@aps.com wrote: > I'm a newbie to Python. I have a list which contains integers (about > 80,000). I want to find a quick way to get the numbers that occur in the > list more than once, and how many times that number is duplicated in the > list. I've done this right now by looping through the list, getting a > number, querying the list to find out how many times the number exists, then > writing it to a new list. On this many records it takes a couple of minutes. > What I am looking for is something in python that can grab this info without > looping through a list. icount = {} for i in list_of_ints: icount[i] = icount.get(i, 0) + 1 Now you have a dictionary of every integer in the list and the count of times it appears. -- D'Arcy J.M. Cain <da...@druid.net> | Democracy is three wolves http://www.druid.net/darcy/ | and a sheep voting on +1 416 425 1212 (DoD#0082) (eNTP) | what's for dinner. Email Firewall made the following annotations --------------------------------------------------------------------- --- NOTICE --- This message is for the designated recipient only and may contain confidential, privileged or proprietary information. If you have received it in error, please notify the sender immediately and delete the original and any copy or printout. Unintended recipients are prohibited from making any other use of this e-mail. Although we have taken reasonable precautions to ensure no viruses are present in this e-mail, we accept no liability for any loss or damage arising from the use of this e-mail or attachments, or for any delay or errors or omissions in the contents which result from e-mail transmission. --------------------------------------------------------------------- -- http://mail.python.org/mailman/listinfo/python-list
