def readcols(infile, cols=None):
    """ Function which reads specified columns from either FITS tables or
        ASCII files

        This function reads in the columns specified by the user into numpy
        arrays regardless of the format of the input table (ASCII or FITS
        table).

        Parameters
        ----------
        infile : string
            Filename of the input file
        cols   : string or list of strings
            Columns to be read into arrays

        Returns
        -------
        outarr : array
            Numpy array or arrays of columns from the table

    """
    if _is_str_none(infile) is None:
        return None

    if infile.endswith('.fits'):
        outarr = read_FITS_cols(infile, cols=cols)
    else:
        outarr = read_ASCII_cols(infile, cols=cols)
    return outarr
Function which reads specified columns from either FITS tables or
        ASCII files

        This function reads in the columns specified by the user into numpy
        arrays regardless of the format of the input table (ASCII or FITS
        table).

        Parameters
        ----------
        infile : string
            Filename of the input file
        cols   : string or list of strings
            Columns to be read into arrays

        Returns
        -------
        outarr : array
            Numpy array or arrays of columns from the table