Fix Pacman "error: duplicated database entry '<package>'" for Arch Linux

fix_pacman_duplicated_database_entry_errors.py

#!/usr/bin/env python

import os,re, datetime
d = '/var/lib/pacman/local'

packages = os.listdir(d)
packages.sort()
packages.remove('ALPM_DB_VERSION')

pkgname_search = re.compile('^(.*?)-[0-9]')

old_packages = []

for pkg1 in packages:
        if pkg1 in old_packages:
                continue
                
        #get package name
        matches = pkgname_search.findall(pkg1)
        print(pkg1)
        if matches == []:
                continue
        pkgname = matches[0]
        
        #look for other items with the same package name
        for pkg2 in packages:
                if pkg2 == pkg1:
                        continue
                if pkg2 in old_packages:
                        continue
                if pkgname == pkgname_search.findall(pkg2)[0]:
                        # We now have two duplicate packages, we want to delete the old one
                        
                        old_package = pkg1
                        path1 = os.path.join(d,pkg1)
                        path2 = os.path.join(d,pkg2)
                        if os.stat(path1).st_mtime > os.stat(path2).st_mtime:
                                old_package = pkg2
                        
                        old_packages.append(old_package)
                        #print ('duplicate found:\t')
                        #print (pkg1)
                        #print (pkg2)
                        #print ('old:', old_package)
                        
                        oldpath = os.path.join(d,old_package)
                        target = os.path.join('/var/lib/pacman/OLD',old_package)
                        cmd = 'mv "%s" "%s"' % (oldpath, target)
                        
                        #double-check that the oldpath still exists (it may have been removed in a previous pass)
                        if os.path.exists(oldpath):
                                print(cmd)
                                os.system(cmd)

Original script from @jeffmikels: https://bbs.archlinux.org/viewtopic.php?pid=1034553#p1034553.

I added line 8 to account for an extra file in that directory on my system, ALPM_DB_VERSION.