def strip_column_names(df):
    """
    Remove leading and trailing single quotes

    Parameters
    ----------
    df : DataFrame
        DataFrame to process

    Returns
    -------
    df : DataFrame
        DataFrame with stripped column names

    Notes
    -----
    In-place modification
    """
    columns = []
    for c in df:
        if c.startswith('\'') and c.endswith('\''):
            c = c[1:-1]
        elif c.startswith('\''):
            c = c[1:]
        elif c.endswith('\''):
            c = c[:-1]
        columns.append(c)
    df.columns = columns
    return df