macOS: Get all local users and calculate the size of the homedirectory

users.py

#!/usr/bin/python
# Get all local users and calculate the size of the homedirectory

import os, pwd, plistlib

system_accounts = ['root', 'daemon', 'nobody', 'Guest']
account_list = []

def get_size(start_path):
    total_size = 0
    for dirpath, dirnames, filenames in os.walk(start_path):
        for f in filenames:
            fp = os.path.join(dirpath, f)
            try:
                total_size += os.path.getsize(fp)
            except Exception as e:
                pass 
    return total_size
    
# Round to .5GB precision (29 bit)
def _HalfGB(size):
    return size >> 29 << 29

for p in pwd.getpwall():
    if  p[0][:1] == '_':
        continue
    if p[0] in system_accounts:
        continue
    if p[5] == '/var/empty':
        continue
    account_list.append({
        'name': p[0],
        'homedir': p[5],
        'size': str(_HalfGB(get_size(p[5])))
    })

print plistlib.writePlistToString(account_list)