Python script to parse the GAM / Google Workspace CSV that contains all members of all groups

# This script will parse the data generated by GAM and create an XLSX out of them.
# Each sheet will be named by the group and it will contain all the emails of that group, including the sub-groups.

# Using sys to get command line arguments for the input file
import sys
# Using CSV to parse the input CSV file that GAM (GAMADV-XTD3) created after using the following command:
# gam print group-members > emails.2022.csv;
# Source: https://bytefreaks.net/google/rough-notes-on-using-gam-to-print-all-members-of-all-groups-in-google-workspace
import csv
# Using pandas to create an XLSX file with multiple sheets
import pandas as pd

# Creating an empty dictionary.
dictionary = {}

# Opening the CSV file that is the first command line argument
with open(sys.argv[1], newline='') as csvfile:
    reader = csv.reader(csvfile, delimiter=',', quotechar='"')
    # For each row, we are getting only the first column which is the group and the last which is the email
    for row in reader:
        dictionary.setdefault(row[0], []).append(row[5])

# Create a Pandas Excel writer using XlsxWriter as the engine.
writer = pd.ExcelWriter(sys.argv[1]+'.xlsx', engine='xlsxwriter')

# Iterating in Sorted Order
for key in sorted(dictionary):
    # Create a Pandas dataframes to add the data.
    df = pd.DataFrame({'Members': dictionary[key]})
    # Write each dataframe to a different worksheet.
    # To avoid the following exception:
    # xlsxwriter.exceptions.InvalidWorksheetName: Excel worksheet name 'action.for.industry.officer@ieeer8.org' must be <= 31 chars.
    # We are truncating the domain from the group.
    group = key.split("@")[0]
    # In case the name is still to big, we truncate it further and append an ellipsis to indicate the extra truncation
    sheet = (group[:29] + '..') if len(group) > 31 else group
    # We are also removing the header and index of the data frame
    df.to_excel(writer, sheet_name=sheet, header=False, index=False)

# Close the Pandas Excel writer and output the Excel file.
writer.close()