Find mode without built in functions or dictionaries

Question

So I have a list of values, and I have an idea of how to get the mode. But I'm unsure of how exactly to execute it. I know I will need the max value of the list using max() and also for x in list,and perhaps creating two lists, one for unique values and the other for how many times they appear, but besides that. I'm completely lost. My list is:

 [0,68, 92, 68, 49, 43, 68]

Expected output:

Sorry if this is vague! This is not a duplicate. I don't want to use a counter function or dictionary. Only lists/ loops.

You say "without using built in functions" and "I know I will need [to use] max()". Which is it? Are you allowed to use builtins or not? — Robᵩ, Dec 05 '17 at 05:49
`lst = [0, 68, 92, 68, 49, 43, 68] numbers = [] freq = [] for number in lst: if number not in numbers: numbers.append(number) freq.append(1) else: index = numbers.index(number) freq[index] += 1 mode = max(zip(numbers, freq), key = lambda x : x[1])[0]` — RoadRunner, Dec 05 '17 at 06:09
@Robᵩ Without built in functions such as Counter, Sum, or Mode. Sorry. — Danielle Jones, Dec 05 '17 at 06:12

score 2 · Answer 1 · answered Dec 05 '17 at 05:47

The mode of a set of data values is the value that appears most often. You can easily get this using python's Counter module's most_common method. It takes n that defines how many results you want, 1 is the most common 2 would be the two most common.

from collections import Counter
data = Counter( [0,68, 92, 68, 49, 43, 68])
print data.most_common(1) 
> [(68, 3)]

most_common: Return a list of the n most common elements and their counts from the most common to the least. If n is omitted or None, most_common() returns all elements in the counter. Elements with equal counts are ordered arbitrarily:

Find mode without built in functions or dictionaries

1 Answers1