Python Forum
Count number of occurrences of list items in list of tuples
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Count number of occurrences of list items in list of tuples
Having a hard time with this one guys-

I need to write a function that takes 3 arguments: data, year_start, year_end.

The data is a list of tuples. year_start and year_end are input by user.

The function needs to count the number of occurrences in 'data', where any year in the date range is in position [0] (position [0] in data is the year).

I need to generate lists of tuples for earthquake_count_by_year = [], and total_damage_by_year = [] in the format [(year, value), (year, value)] for each year in the range.

Here's what I have:

def summary_statistics(data, year_start, year_end):
    earthquake_count_by_year = []
    total_damages_by_year = []
    casualties_by_year = []
    count = 0
    years = []
    year_start = int(year_start)
    year_end = int(year_end)
    if year_end >= year_start:
        # store range of years into list
        years = list(range(year_start, year_end+1))
        for index, tuple in enumerate(data):
            if tuple[0] in years:
                count[tuple[0]] += 1
The above is just my attempt to count the number of occurrences in the input for each year. I feel like if I can get this much, I can figure out the rest.

Here is the input for "data":
[(2020, 1, 6.0, 'CHINA:  XINJIANG PROVINCE', 39.831, 77.106, 1, 0, 2, 0), (2020, 1, 6.7, 'TURKEY:  ELAZIG AND MALATYA PROVINCES', 38.39, 39.081, 41, 0, 1600, 0), (2018, 1, 7.7, 'CUBA: GRANMA;  CAYMAN IS;  JAMAICA', 19.44, -78.755, 0, 0, 0, 0), (2019, 2, 6.0, 'TURKEY: VAN;  IRAN', 38.482, 44.367, 10, 0, 60, 0), (2018, 3, 5.4, 'BALKANS NW:  CROATIA:  ZAGREB', 45.897, 15.966, 1, 0, 27, 6000.0), (2020, 3, 5.7, 'USA: UTAH', 40.751, -112.078, 0, 0, 0, 48.5), (2020, 3, 7.5, 'RUSSIA:  KURIL ISLANDS', 48.986, 157.693, 0, 0, 0, 0)]
Start with writing the test to determine if a date is in the specified range. Can you do that? You don't need anything fancy like datetime, just check if a number is in a range. What you have is not going to work. It would only match the year_start or year_end, not the values inbetween. item in
  • returns True if item matches something in the list, it is not interpreting the list as a range.

    The way you were trying to keep count wasn't going to work either. You treat count as an integer and as a list. You can't do that. You will probably want count to be a collection of some kind. I would use a dictionary where the key is the year and the value is the count.
    if tuple[0] in years:
        count[tuple[0]] = count.get(tuple[0], 0) + 1
    Like the comparison I would work this part independently too. Try adding a few years to your count and then print the count to see if it works.

    It is easier to solve small problems than big problems. If you cannot figure out how to write a program to solve a big problem, first write a program to solve a small piece of the big program. Then write another programe to solve a different piece.

    That's how I solved this problem. First I wrote something that generated a random list of numbers in the range 1900 to 2020 to represent your earthquake data. Then I write a little loop to print True or False based on if the year in the list was in the range 1996 to 2020. Then I wrote the dictionary part to save the years that are in that range, and finally I wrote the part that incremented the count each time a year was found. A bunch of little programming tasks that were fairly simple but added up to a good working example.

Possibly Related Threads…
Thread Author Replies Views Last Post
  List of error codes to find (and count) in all files in a directory tester_V 8 303 Dec-11-2020, 07:07 PM
Last Post: tester_V
  Adding List Element if Second part of the List Elements are the Same quest_ 3 209 Nov-25-2020, 04:33 PM
Last Post: bowlofred
  Need help improving function that reads file into list of tuples t4keheart 6 252 Nov-03-2020, 04:58 AM
Last Post: ndc85430
  How do I add a number to every item in a list? john316 2 155 Oct-28-2020, 05:29 PM
Last Post: deanhystad
  concatenating 2 items at a time in a python list K11 3 244 Oct-21-2020, 09:34 AM
Last Post: buran
Question Save list with nested list into CSV SpongeB0B 1 355 Oct-12-2020, 07:26 AM
Last Post: bowlofred
  Appending to list of list in For loop nico_mnbl 2 273 Sep-25-2020, 04:09 PM
Last Post: nico_mnbl
  Count & Sort occurrences of text in a file oradba4u 7 416 Sep-06-2020, 03:23 PM
Last Post: oradba4u
  How to make a list of values from a dictionary list? faryad13 2 328 Sep-03-2020, 03:45 PM
Last Post: faryad13
  Select the other of 2 items in a list Clunk_Head 7 545 Sep-01-2020, 05:27 PM
Last Post: Clunk_Head

Forum Jump:

User Panel Messages

Announcement #1 8/1/2020
Announcement #2 8/2/2020
Announcement #3 8/6/2020