regular expression language for expressing more complex search strings regular expression may contain special characters that indicate that search only matches at the beginning or end of line or many other similar capabilities wild card special character that matches any character in regular expressions the wild-card character is the period exercises exercise write simple program to simulate the operation of the grep command on unix ask the user to enter regular expression and count the number of lines that matched the regular expressionpython grep py enter regular expression^author mbox txt had lines that matched ^author python grep py enter regular expression^xmbox txt had lines that matched ^xpython grep py enter regular expressionjavambox txt had lines that matched javaexercise write program to look for lines of the formnew revision extract the number from each of the lines using regular expression and the findall(method compute the average of the numbers and print out the average as an integer enter file:mbox txt enter file:mbox-short txt