Section 12.12 Write Code Questions
Some of the questions use the data file mbox
Checkpoint 12.12.1.
Modify the ### to find sequences with one uppercase letter followed by an underscore followed by one or more lowercase letters.
Solution.Modify the ### to find sequences with one uppercase letter followed by an underscore followed by one or more lowercase letters.
# Line 1: import re
# Line 3: [A-Z] matches uppercase letter characters and [a-z] matches lowercase letter characters
# Line 4: Use the pattern variable to search the text
# Line 6: Include the else statement
import re
def text_match(text):
pattern = '[A-Z]_[a-z]+'
if re.search(pattern, text):
return('Found a match!')
else:
return('Not matched!')
print(text_match("aab_cbbbc"))
====
from unittest.gui import TestCaseGui
class MyTests(TestCaseGui):
def testOne(self):
self.assertEqual(text_match("aab_cbbc"), "Not matched!", 'text_match("aab_cbbc")')
self.assertEqual(text_match("aaA_bbbc"), "Found a match!", 'text_match("aaA_bbbc")')
self.assertEqual(text_match("A_abbbc"), "Found a match!", 'text_match("A_abbbc")')
self.assertEqual(text_match("word_A"), "Not matched!", 'text_match("word_A")')
self.assertEqual(text_match("myZ_oo"), "Found a match!", 'text_match("myZ_oo")')
MyTests().main()
Checkpoint 12.12.2.
Complete the code below to check if a string begins with a word character. If it does, return “Found a match!”, if not return “Not matched!” Replace the ### with your code.
Checkpoint 12.12.3.
Define the function “match_four” that takes a string and uses regex to return True if the string starts with 4 followed by zero to many other digits and False if it does not.
Solution.Define the function “match_four” that takes a string and uses regex to return True if the string starts with 4 followed by zero to many other digits and False if it does not.
# First import the regex library (re), then define the match_four function.
# Within the function, create the regex pattern to match if the string starts with '4'
# Use an if statement to check for a match in the string.
# Return true if the match is made, return false if not.
import re
def match_four(string):
pattern = "^4\d*"
if re.search(pattern, string):
return True
else:
return False
====
from unittest.gui import TestCaseGui
class MyTests(TestCaseGui):
def testOne(self):
self.assertEqual(match_four("468653892"), True, 'match_four("468653892")')
self.assertEqual(match_four("648653892"), False, 'match_four("648653892")')
self.assertEqual(match_four("41"), True, 'match_four("41")')
self.assertEqual(match_four("4"), True, 'match_four("4")')
self.assertEqual(match_four("786328042"), False, 'match_four("786328042")')
MyTests().main()
Checkpoint 12.12.4.
Define the function “match_cat” that uses regex to return True if a string matches cat, Cat, CAT, cAt, etc and False if it does not.
Checkpoint 12.12.5.
Define the function match_z to match a word containing a lowercase letter z. Return "Found a match!" if z is in the string and "Not matched!" if there is not a z.
Solution.Define the function match_z to match a word containing a lowercase letter z. Return "Found a match!" if z is in the string and "Not matched!" if there is not a z.
# In the function definition, create a regex pattern to find 'z'
# Search the string with that pattern using re.search()
# If found, return "Found a match!"
# Otherwise, return "Not matched!"
import re
def match_z(text):
patterns = '\w*z\w*'
if re.search(patterns, text):
return 'Found a match!'
else:
return('Not matched!')
====
from unittest.gui import TestCaseGui
class MyTests(TestCaseGui):
def testOne(self):
self.assertEqual(match_z("The lazy dog."), "Found a match!", 'match_z("The lazy dog.")')
self.assertEqual(match_z("Python rocks!"), "Not matched!", 'match_z("Python rocks!")')
self.assertEqual(match_z("Zippers"), "Not matched!", 'match_z("Zippers")')
self.assertEqual(match_z("pez"), "Found a match!", 'match_z("pez")')
self.assertEqual(match_z("abc"), "Not matched!", 'match_z("abc")')
MyTests().main()
Checkpoint 12.12.6.
Define the function matchMiddle_z to match a word containing the letter z, but not at the beginning or end of a word. Return “Found a match!” if z is in the string and “Not matched!” if there is not a z.
Checkpoint 12.12.7.
Finish the code below to find all of the emails in “mbox-short.txt” and add them to a list and return the list. An email starts with an alphanumeric character followed by one or more non white space characters and then “@” followed by one or more non white space characters with one alphabetic character at the end.
Solution.Finish the code below to find all of the emails in “mbox-short.txt” and add them to a list and return the list. An email starts with an alphanumeric character followed by one or more non white space characters and then “@” followed by one or more non white space characters with one alphabetic character at the end.
# First import regex (re) and create a handle for the file.
# Initialize a list to hold the emails.
# Iterate through each line in the file, using rstrip() to remove whitespace and findall() with a regex expression to find the emails.
# Add each email to the list, individually
# Print the email list after each loop has completed.
import re
hand = open('mbox-short.txt')
email_list = []
for line in hand:
line = line.rstrip()
x = re.findall('[a-zA-Z0-9]\S+@\S+[a-zA-Z]', line)
for email in x:
email_list.append(x)
print(email_list)
====
from unittest.gui import TestCaseGui
class MyTests(TestCaseGui):
def testOne(self):
self.assertEqual(email_list, [['gopal.ramasammycook@gmail.com'], ['louis@media.berkeley.edu'], ['cwen@iupui.edu'], ['antranig@caret.cam.ac.uk'], ['rjlowe@iupui.edu'], ['gsilver@umich.edu'], ['david.horwitz@uct.ac.za'], ['wagnermr@iupui.edu'], ['zqian@umich.edu'], ['stephen.marquard@uct.ac.za'], ['ray@media.berkeley.edu']], "Testing that all the emails were matched.")
MyTests().main()
Checkpoint 12.12.8.
Using “mbox-short.txt”, extract the email domains from each email address using regex and add them to the list “domains”. For the email
noname@umich.edu 1 , this would locate the string “umich.edu”.
Checkpoint 12.12.9.
Using “mbox-short.txt”, extract the number next to each email (the amount of emails each person has sent) using a regex equation, and calculate the total amount of emails sent. Save this to the variable ‘total_emails'. Use the () character to capture and return the number.
Solution.Using “mbox-short.txt”, extract the number next to each email (the amount of emails each person has sent) using a regex equation, and calculate the total amount of emails sent. Save this to the variable ‘total_emails'. Use the () character to capture and return the number.
# Import regex (re), create a variable for the total number of emails, and create a handle to access the file.
# Iterate through lines in the file, remove trailing whitespace with rstrip(), and create a regex expression to use with findall() to return a list of email matches.
# Finally, increment the total_emails variable for each email in the list
# Print the variable after each loop has completed.
import re
total_emails = 0
hand = open('mbox-short.txt')
for line in hand:
line = line.rstrip()
x = re.findall('[a-zA-Z0-9]\S+@\S+[a-zA_Z]\s?(\d)', line)
for item in x:
total_emails += int(item)
print(total_emails)
====
from unittest.gui import TestCaseGui
class MyTests(TestCaseGui):
def testOne(self):
self.assertEqual(total_emails, 27, "Testing that the average was calculated properly.")
MyTests().main()
Checkpoint 12.12.10.
Using “mbox-short.txt”, extract the usernames from each email address using regex and add them to the list “usernames”. For the email
noname@umich.edu 2 , this would locate the string “noname”.
