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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 _load_cytoBand(filename):
 """ Load UCSC cytoBand table. Parameters filename : str path to cytoBand file Returns ------- df : pandas.DataFrame cytoBand table if loading was successful, else None References ..[1] Ryan Dale, GitHub Gist, https://gist.github.com/daler/c98fc410282d7570efc3#file-ideograms-py """

        try:
            # adapted from chromosome plotting code (see [1]_)
            df = pd.read_table(
                filename, names=["chrom", "start", "end", "name", "gie_stain"]
            )
            df["chrom"] = df["chrom"].str[3:]
            return df
        except Exception as err:
            print(err)
            return None