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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 getTempFile(suffix="", rootDir=None):
 """Returns a string representing a temporary file, that must be manually deleted """

    if rootDir is None:
        handle, tmpFile = tempfile.mkstemp(suffix)
        os.close(handle)
        return tmpFile
    else:
        tmpFile = os.path.join(rootDir, "tmp_" + getRandomAlphaNumericString() + suffix)
        open(tmpFile, 'w').close()
        os.chmod(tmpFile, 0777) #Ensure everyone has access to the file.
        return tmpFile