GetGroupsWithMatchingMembers.py

#!/usr/bin/env python3
"""
# Purpose: Produce a CSV file showing groups with members that match regular expressions
# Note: This script can use Basic or Advanced GAM:
#	https://github.com/GAM-team/GAM
#	https://github.com/taers232c/GAMADV-XTD3
# Customize: USER_MATCH_PATTERN, GROUP_MATCH_PATTERN, SHOW_GROUPS_WITH_NO_MATCHES
# Python: Use python or python3 below as appropriate to your system; verify that you have version 3
#  $ python -V   or   python3 -V
#  Python 3.x.y
# Usage:
# 1: Get group members
#  $ Basic: gam print group-members fields email,type > GroupMembers.csv
#  $ Advanced: gam redirect csv ./GroupMembers.csv print group-members fields email,type
# 2: From that list of group members, output a CSV file with headers group,groupMatches,groupTotal,userMatches,userTotal
#  $ python3 GetGroupsWithMatchingMembers.py ./GroupMembers.csv ./GroupsWithMatchingMembers.csv
# 3: If you want a list of the matching members, add another filename to the command, the matching members will be output to that file
#  $ python3 GetGroupsWithMatchingMembers.py ./GroupMembers.csv ./GroupsWithMatchingMembers.csv ./MatchingMembers.csv
# 4: If you want to delete the matching members from their groups, you can do the following which uses one API call per member
#  $ gam csv ./MatchingMembers.csv gam update group "~group" delete member "~email"
# 5: With Advanced GAM, you can delete the members in batches
#  $ gam update group csvkmd ./MatchingMembers.csv keyfield group datafield email delete member csvdata email
"""

import csv
import re
import sys

QUOTE_CHAR = '"' # Adjust as needed
LINE_TERMINATOR = '\n' # On Windows, you probably want '\r\n'

# Python regular expressions; r'' indicates no matching
USER_MATCH_PATTERN = r''
GROUP_MATCH_PATTERN = r''

# Should groups with no matches be shown
SHOW_GROUPS_WITH_NO_MATCHES = False

# Indexes into group counts
GROUP_MATCHES = 0
GROUP_TOTAL = 1
USER_MATCHES = 2
USER_TOTAL = 3

if USER_MATCH_PATTERN:
  try:
    userMatchPattern = re.compile(USER_MATCH_PATTERN)
  except re.error as e:
    print(f'Error: invalid USER_MATCH_PATTERN: "{USER_MATCH_PATTERN}", {e}')
    sys.exit(1)
else:
  userMatchPattern = None

if GROUP_MATCH_PATTERN:
  try:
    groupMatchPattern = re.compile(GROUP_MATCH_PATTERN)
  except re.error as e:
    print(f'Error: invalid GROUP_MATCH_PATTERN: "{GROUP_MATCH_PATTERN}", {e}')
    sys.exit(1)
else:
  groupMatchPattern = None

if (len(sys.argv) > 2) and (sys.argv[2] != '-'):
  outputFile = open(sys.argv[2], 'w', encoding='utf-8', newline='')
else:
  outputFile = sys.stdout
outputCSV = csv.DictWriter(outputFile, ['group', 'groupMatches', 'groupTotal', 'userMatches', 'userTotal'], lineterminator=LINE_TERMINATOR, quotechar=QUOTE_CHAR)
outputCSV.writeheader()

if (len(sys.argv) > 1) and (sys.argv[1] != '-'):
  inputFile = open(sys.argv[1], 'r', encoding='utf-8')
else:
  inputFile = sys.stdin
inputCSV = csv.DictReader(inputFile, quotechar=QUOTE_CHAR)

if len(sys.argv) > 3:
  matchFile = open(sys.argv[3], 'w', encoding='utf-8', newline='')
  matchCSV = csv.DictWriter(matchFile, inputCSV.fieldnames, lineterminator=LINE_TERMINATOR, quotechar=QUOTE_CHAR)
  matchCSV.writeheader()
else:
  matchFile = None

Groups = {}
for row in inputCSV:
  if row['type'] in ['USER', 'GROUP']:
    group = row['group']
    Groups.setdefault(group, [0, 0, 0, 0])
    emailAddress = row['email']
    if row['type'] == 'USER':
      Groups[group][USER_TOTAL] += 1
      if userMatchPattern and userMatchPattern.match(emailAddress):
        Groups[group][USER_MATCHES] += 1
        if matchFile:
          matchCSV.writerow(row)
    elif row['type'] == 'GROUP':
      Groups[group][GROUP_TOTAL] += 1
      if groupMatchPattern and groupMatchPattern.match(emailAddress):
        Groups[group][GROUP_MATCHES] += 1
        if matchFile:
          matchCSV.writerow(row)

if matchFile:
  matchFile.close()

for group, counts in sorted(iter(Groups.items())):
  if SHOW_GROUPS_WITH_NO_MATCHES or counts[GROUP_MATCHES] or counts[USER_MATCHES]:
    outputCSV.writerow({'group': group,
                        'groupMatches': counts[GROUP_MATCHES],
                        'groupTotal': counts[GROUP_TOTAL],
                        'userMatches': counts[USER_MATCHES],
                        'userTotal': counts[USER_TOTAL],
                       })

if inputFile != sys.stdin:
  inputFile.close()
if outputFile != sys.stdout:
  outputFile.close()