Python Exercise 11: Count the number and generate new dictionary

Question

• Write a program to iterate a given list and count the occurrence of each element and create a to show the count of each element.
• Given:

sample_list = [11, 45, 8, 11, 23, 45, 23, 45, 89] 

• Expected Output:

Printing count of each item {11: 2, 45: 3, 8: 1, 23: 2, 89: 1} 

My solution

1. initiate an empty dictionary
2. initiate an counter
3. iterate over the sample_list
   • 3.1 for each number, count the occurrence of that number in sample
   • 3.2 use setdefault() method to add the number as key and occurrence as value to dictionary

sample_list = [11, 45, 8, 11, 23, 45, 23, 45, 89] count_dictionary = dict() occurrence = 0 for number in sample_list: occurrence = sample_list.count(number) count_dictionary.setdefault(number, occurrence) print(f"Printing count of each item {count_dictionary}") 

Other Solution

1. initiate an empty dictionary
2. iterate over the sample_list
   • 2.1 check if the number appear in the dictionary
     • 2.1.1 if the number does not appear in the dictionary, add the number as key and 1 as value to the dictionary
     • 2.1.2 if the appear in the dictionary, increase the value by 1.

sample_list = [11, 45, 8, 11, 23, 45, 23, 45, 89] print("Original list ", sample_list) count_dict = dict() for item in sample_list: if item in count_dict: count_dict[item] += 1 else: count_dict[item] = 1 print("Printing count of each item ", count_dict) 

Credit

exercise on Pynative