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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_ignorer(path, additional_exclusions=None):
 """Create ignorer with directory gitignore file."""

    ignorefile = zgitignore.ZgitIgnore()
    gitignore_file = os.path.join(path, '.gitignore')
    if os.path.isfile(gitignore_file):
        with open(gitignore_file, 'r') as fileobj:
            ignorefile.add_patterns(fileobj.read().splitlines())

    if additional_exclusions is not None:
        ignorefile.add_patterns(additional_exclusions)

    return ignorefile