Question

use python to write and submit a script that asks for a filename (to which mbox.txt and mbox-short.txt will be used) and looks for lines of the form

New Revision: 39772

Extract the number from each of the lines using a regular expression and the findall() method. Compute the average of the numbers, rounded to a single decimal place, and print out the average and the number of lines used for the computation.

Enter filename: mbox.txt

Average = 38549.8

Number of lines = 1790

Enter filename: mbox-short.txt

Average = 39756.9

Number of lines = 27

Answer 1

import re
def extractNumber(input,lst):
numbers = re.findall('\d+',input)
for num in numbers :
lst.append(int(num))
def Average(lst):
return float(sum(lst) / len(lst))   
# Driver program
if __name__ == "__main__":
filename = input("Enter filename: ")
lst = []
f = open(filename)
line = f.readline()
count = 0
while line:
extractNumber(line,lst)
line = f.readline()
count = count + 1
f.close()
print("Average = ", Average(lst))
print("Number of lines = ",count)