human
Complete the below
def alias(aliasPath, sourcePath):

    ''''I am not a very good aliaser. But I\'m the best I can be. If I\'m
    aliasing to a Resource that generates links, and it uses any parts
    of request.prepath to do so, the links will not be relative to the
    aliased path, but rather to the aliased-to path. That I can\'t
    alias static.File directory listings that nicely. However, I can
    still be useful, as many resources will play nice.'
    '''
 ... Give me a the Python program you requested?
assistant
#Here is the Python program you requested.
    sourcePath = sourcePath.split('/')
    aliasPath = aliasPath.split('/')
    def rewriter(request):
        if (request.postpath[:len(aliasPath)] == aliasPath):
            after = request.postpath[len(aliasPath):]
            request.postpath = (sourcePath + after)
            request.path = ('/' + '/'.join((request.prepath + request.postpath)))
    return rewriter