### utility modules from csv import reader import datetime as dt ### utility functions # opens the file and returns the header and the data def open_dataset(file_path): opened_file = open(file_path) read_file = reader(opened_file) dataset = list(read_file) dataset_header = dataset[0] dataset = dataset[1:] return dataset_header, dataset # prints header and row information of a dataset def explore_data(dataset, header, start, end): dataset_slice = dataset[start:end] print(header, "\n") for row in dataset_slice: print(row) print("\nNumber of rows", len(dataset)) print("Number of columns", len(dataset[0])) # returns the average number of comments for a posts category def find_average_num_comments(posts): num_comments = 0 for post in posts: num_comments += int(post[4]) avg_num_comments = num_comments / len(posts) return round(avg_num_comments, 2) # returns the post counts and comment counts by hour created def find_post_and_comment_counts_by_hour(posts): formatted_posts = [] for post in posts: formatted_posts.append([post[6], int(post[4])]) counts_by_hour = {} comments_by_hour = {} for created_at, num_comments in formatted_posts: date_object = dt.datetime.strptime(created_at, "%m/%d/%Y %H:%M") hour = date_object.strftime("%H") if hour in counts_by_hour: counts_by_hour[hour] += 1 comments_by_hour[hour] += num_comments else: counts_by_hour[hour] = 1 comments_by_hour[hour] = num_comments return counts_by_hour, comments_by_hour # displays a given frequency table, sorted from highest to lowest def display_freq_table(freq_table, label = ""): converted_freq_table = [] for key in freq_table: converted_freq_table.append((freq_table[key], key)) for value, key in sorted(converted_freq_table, reverse=True)[:5]: print(key, ":", value, label)

# extract the dataset, separating the header from the rest of the data hn_header, hn = open_dataset("HN_posts_year_to_Sep_26_2016.csv") # print header and row information of the hn dataset explore_data(hn, hn_header, 0, 5)

ask_hn_posts = [] show_hn_posts = [] other_hn_posts = [] # seperate the posts into ask_hn, show_hn and other_hn for post in hn: title = post[1].lower() if title.startswith("ask hn"): ask_hn_posts.append(post) elif title.startswith("show hn"): show_hn_posts.append(post) else: other_hn_posts.append(post) # print number of posts in each category template = "{}: {} | {:.2f}%" print(template.format("Number of Ask HN Posts", len(ask_hn_posts), len(ask_hn_posts) / len(hn) * 100)) print(template.format("Number of Show HN Posts", len(show_hn_posts), len(show_hn_posts) / len(hn) * 100)) print(template.format("Number of Other HN Posts", len(other_hn_posts), len(other_hn_posts) / len(hn) * 100))

# finds the average number of comments for each posts category avg_ask_comments = find_average_num_comments(ask_hn_posts) avg_show_comments = find_average_num_comments(show_hn_posts) avg_other_comments = find_average_num_comments(other_hn_posts) # prints that information in human-readable form template = "{:}: {} comments per post" print(template.format("Avg Ask HN", avg_ask_comments)) print(template.format("Avg Show HN", avg_show_comments)) print(template.format("Avg Other HN", avg_other_comments))

# finds the number of counts and comments by hour of the post created for the ask_hn_posts category ask_counts_by_hour, ask_comments_by_hour = find_post_and_comment_counts_by_hour(ask_hn_posts) print("\nNumber of comments by hour post created\n---") display_freq_table(ask_comments_by_hour, "posts")

# finds the number of counts and comments by hour of the post created for the show_hn_posts category show_counts_by_hour, show_comments_by_hour = find_post_and_comment_counts_by_hour(show_hn_posts) print("\nNumber of comments by hour post created\n---") display_freq_table(show_comments_by_hour, "posts")

# finds the number of counts and comments by hour of the post created for the show_hn_posts category other_counts_by_hour, other_comments_by_hour = find_post_and_comment_counts_by_hour(other_hn_posts) print("\nNumber of comments by hour post created\n---") display_freq_table(other_comments_by_hour, "posts")

avg_ask_comments_by_hour = {} for hour in ask_counts_by_hour: avg_ask_comments_by_hour[hour] = round(ask_comments_by_hour[hour] / ask_counts_by_hour[hour], 2) print("\nAvg number of comments by hour post created\n---") display_freq_table(avg_ask_comments_by_hour, "avg comments")

avg_show_comments_by_hour = {} for hour in show_counts_by_hour: avg_show_comments_by_hour[hour] = round(show_comments_by_hour[hour] / show_counts_by_hour[hour], 2) print("\nAvg number of comments by hour post created\n---") display_freq_table(avg_show_comments_by_hour, "avg comments")

avg_other_comments_by_hour = {} for hour in other_counts_by_hour: avg_other_comments_by_hour[hour] = round(other_comments_by_hour[hour] / other_counts_by_hour[hour], 2) print("\nAvg number of comments by hour post created\n---") display_freq_table(avg_other_comments_by_hour, "avg comments")