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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 strip_chr(bt):
 """Strip 'chr' from chromosomes for BedTool object Parameters bt : pybedtools.BedTool BedTool to strip 'chr' from. Returns ------- out : pybedtools.BedTool New BedTool with 'chr' stripped from chromosome names. """

    try:
        df = pd.read_table(bt.fn, header=None, dtype=str)
    # If the try fails, I assume that's because the file has a trackline. Note
    # that I don't preserve the trackline (I'm not sure how pybedtools keeps
    # track of it anyway).
    except pd.parser.CParserError:
        df = pd.read_table(bt.fn, header=None, skiprows=1, dtype=str)
    df[0] = df[0].apply(lambda x: x[3:])
    s = '\n'.join(df.astype(str).apply(lambda x: '\t'.join(x), axis=1)) + '\n'
    out = pbt.BedTool(s, from_string=True)
    return out