Join strings with different delimiters and some possibly empty strings I want to construct a string from several substrings, each one of those with a different delimiter. If the string is present, the delimiter and the string should be added, if not, none of them should be added. 

This is my current code that looks a bit dirty to me:

def my_join(major, minor, patch=None, pre_release=None, build=None, revision=None):

   version = '.'.join(filter(None,(major, minor, patch)))

   if pre_release: version += '-%s'  % pre_release
   if build:       version += '+b%s' % build
   if revision:    version += '.%s'  % revision

   return version



my_join('0', '1',pre_release='alpha')
'0.1-alpha'
my_join('2','3','4', build='567', revision='aabbcc440')
'2.3.4+b567.aabbcc440'



My problem is basically an extension of join 4 strings to the one if they are not empty in python with the addition of using different delimiter strings.
It doesn't look too bad to me; I'd make a few changes.

def my_join(major, minor, patch=None, prerelease=None,
            build=None, revision=None):
    version_parts = ['.'.join((major, minor, patch or ''))]

    if prerelease:
        version_parts.append('-%s' % prerelease)
    if build:
        version_parts.append('+b%s' % build)
    if revision:
        version_parts.append('.%s' % revision)

    version = ''.join(version_parts)

    return version


Instead of building the string piece-by-piece, this code adds the needed parts to a list which is then joined at the end. I also removed the overpowered call to filter, and instead used or to make the patch value be '' if patch is False-ish, as it would be if patch is None.