Question

(Python) Develop a crawler that collects the email addresses in the visited web pages. You can write a function emails() that takes a document (as a string) as input and returns the set of email addresses (i.e., strings) appearing in it. You should use a regular expression to find the email addresses in the document. Explain the code and how it works.

Answer 1

Program: File name: Main.py #import necessary header files import re from urllib.request import urlopen wwwwo wwww m emails ()" #Define the function w wwwwwww. def emails (document) #Declare the list 11 = ww #For loop to print the list of email addresses for email in re.findall (r'I\w\.-] +@ [ \w\ .-]+', document) wwwwM #Check, email is not in list if not email in l1: #Then, add the email to the list "11" 11.append (email) wwdwb #Print the list "l1" print (11)

#Assign the webpage url = www 'http://www.cdm.depaul.edu #Assign the content into the variable "document" document = urlopen (url).read () .decode () wwwwwww hwwww emails )" #Call the function emails (document) Output: ['[email protected]', '[email protected]', 'wwwfee [email protected]'

Editable code:

#import necessary header files

import re

from urllib.request import urlopen

#Define the function "emails()"

def emails(document):

#Declare the list

l1 =[]

#For loop to print the list of email addresses

for email in re.findall(r'[\w\.-]+@[\w\.-]+', document):

#Check, email is not in list

if not email in l1:

#Then, add the email to the list "l1"

l1.append(email)

#Print the list "l1"

print(l1)

#Assign the webpage

url = 'http://www.cdm.depaul.edu'

#Assign the content into the variable "document"

document = urlopen(url).read().decode()

#Call the function "emails()"

emails(document)