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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_init_release_tag(self):
 """ parses init.py to get previous version """

        self.init_version = re.search(r"^__version__ = ['\"]([^'\"]*)['\"]",
                                      open(self.init_file, "r").read(),
                                      re.M).group(1)