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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 new_plugin(odir, py_name=None, version='0.0.1.dev0', description='New plugin'):
 """ Create a new plugin for the psyplot package Parameters odir: str The name of the directory where the data will be copied to. The directory must not exist! The name of the directory also defines the name of the package. py_name: str The name of the python package. If None, the basename of `odir` is used (and ``'-'`` is replaced by ``'_'``) version: str The version of the package description: str The description of the plugin"""

    name = osp.basename(odir)
    if py_name is None:
        py_name = name.replace('-', '_')

    src = osp.join(osp.dirname(__file__), 'plugin-template-files')
    # copy the source files
    shutil.copytree(src, odir)
    os.rename(osp.join(odir, 'plugin_template'), osp.join(odir, py_name))

    replacements = {'PLUGIN_NAME': name,
                    'PLUGIN_PYNAME': py_name,
                    'PLUGIN_VERSION': version,
                    'PLUGIN_DESC': description,
                    }
    files = [
        'README.md',
        'setup.py',
        osp.join(py_name, 'plugin.py'),
        osp.join(py_name, 'plotters.py'),
        osp.join(py_name, '__init__.py'),
        ]

    for fname in files:
        with open(osp.join(odir, fname)) as f:
            s = f.read()
        for key, val in replacements.items():
            s = s.replace(key, val)
        with open(osp.join(odir, fname), 'w') as f:
            f.write(s)