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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 corpusindex():
 """Get list of pre-installed corpora"""

        corpora = []
        for f in glob.glob(settings.ROOT + "corpora/*"):
            if os.path.isdir(f):
                corpora.append(os.path.basename(f))
        return corpora