Odtnhj

I am trying to utilize a single for loop in Python to

1. Check for the largest number within a list then print the index it was found



2. 
   

   Count the frequency of that largest number within the list.

   
   
   

   for index in range(1, listLength):
    if numbersList[index] > numbersList[largest]:
    largest = index
   

   
   

I have part 1 complete, however, I am unsure how I can then search for the frequency of it within the same for loop.

Thanks for your help.

You don't have to use the loop at all to achieve this. Sort the list and find the number at the last index and use count(number) to get the number of occurences.

numbers = [1, 3, 4, 2, 3, 4, 5]
numbers.sort() 
print(numbers) 
[1, 2, 3, 3, 4, 4, 5]

list.count(number)

[1, 2, 3, 3, 4, 4, 5].count(5)
1

or you can use import the below one

 from collections import Counter
 Counter(list)

will give you the output count in dictionary format.

Counter('1': 1, '2': 1, '3': 2, '4': 2, '5': 1)

There are few ways around this

a = [1, 9, 3, 7, 5, 9, 7, 4, 9, 5] # test_data

1. 
   

   max() and count

   
   
   

   largest = max(a)
   print(largest) # 9
   print(a.count(largest)) # 3
   

   
   
   

   Usually, above is the most common and widely used way of getting largest number and counting elements in the list.

   
   


2. 
   

   max() and Counter

   
   
   

   from collections import Counter
   c = Counter(a)
   print(c[max(a)]) # 3
   

   
   
   

   Counter is from collections and it supports various kinds of methods. For more, please refer to this website: https://data-flair.training/blogs/python-counter/

   
   

There are inbuilt methods to do these.

In [110]: lst = [1,2,4,5,66,7,7,4,66,78,1]
In [111]: max(lst)
Out[111]: 78

1.Check for the largest number within a list then print the index it was found,

In [112]: print lst.index(max(lst))
Out[112]: 9

2.Count the frequency of that largest number within the list.

In [113]: print lst.count(max(lst))
Out[113]: 1

If you are not allowed to use built-in functions then, take an integer e.g Count. This represents the frequency of the largest number. Go through the array once and when you find a new largest number set largest = index and counter = 0. Add a condition that if the current number is equal to your saved largest number then increment the count by 1.

If you don't want to use any libraries, you can achieve it by using below code:

counter = 1
for index in range(listLength):
 if index == 0:
 largest = 0
 if numbersList[index] == numbersList[largest]:
 counter += 1
 elif numbersList[index] > numbersList[largest]:
 counter = 1
 largest = index