Script replaces given domain to another from a csv

Draft (but working) script that replaces given domain to another, data exctracted from a csv

Author: mottamx

replacedomain.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+import re
+import csv
+def contains_domain(address, domain):
+  """Returns True if the email address contains the given,domain,in the domain position, false if not."""
+  domain = r'[\w\.-]+@'+domain+'$'
+  if re.match(domain,address):
+    return True
+  return False
+def replace_domain(address, old_domain, new_domain):
+  """Replaces the old domain with the new domain in the received address."""
+  old_domain_pattern = r'' + old_domain + '$'
+  address = re.sub(old_domain_pattern, new_domain, address)
+  return address
+def main():
+  """Processes the list of emails, replacing any instances of the old domain with the new domain."""
+  old_domain, new_domain = 'abc.edu', 'xyz.edu'
+  csv_file_location = '/home/<username>/data/user_emails.csv'
+  report_file = '<path_to_home_directory>' + '/updated_user_emails.csv'
+  user_email_list = []
+  old_domain_email_list = []
+  new_domain_email_list = []
+  with open(csv_file_location, 'r') as f:
+    user_data_list = list(csv.reader(f))
+    user_email_list = [data[1].strip() for data in user_data_list[1:]]
+    for email_address in user_email_list:
+      if contains_domain(email_address, old_domain):
+        old_domain_email_list.append(email_address)
+        replaced_email = replace_domain(email_address,old_domain,new_domain)
+        new_domain_email_list.append(replaced_email)
+    email_key = ' ' + 'Email Address'
+    email_index = user_data_list[0].index(email_key)
+    for user in user_data_list[1:]:
+      for old_domain, new_domain in zip(old_domain_email_list, new_domain_email_list):
+        if user[email_index] == ' ' + old_domain:
+          user[email_index] = ' ' + new_domain
+  f.close()
+  with open(report_file, 'w+') as output_file:
+    writer = csv.writer(output_file)
+    writer.writerows(user_data_list)
+    output_file.close()
+	
+main()
+