+from csv import DictReader
+
+# read in the input file and count by day
+input_file = open("hp_wiki.csv", 'r')
+
+edits_by_day = {}
+for row in DictReader(input_file):
+ day_string = row['timestamp'][0:10]
+
+ if day_string in edits_by_day:
+ edits_by_day[day_string] = edits_by_day[day_string] + 1
+ else:
+ edits_by_day[day_string] = 1
+
+input_file.close()
+
+# output the counts by day
+output_file = open("hp_edits_by_day.csv", "w")
+
+# write a header
+output_file.write("date,edits\n")
+
+# iterate through every day and print out data into the file
+for day_string in edits_by_day:
+ output_file.write(",".join([day_string, str(edits_by_day[day_string])]) + "\n")
+
+output_file.close()