def get_merged_columns(original_df, merged_df, suffix):
    """Gets the columns from an original dataframe, in the new merged dataframe

    Parameters
    ----------
    original_df : Pandas.DataFrame
        The original, pre-merge dataframe
    merged_df : Pandas.DataFrame
        Post-merge with another dataframe, with suffixes added in.
    suffix : str
        What suffix was used to distinguish when the original dataframe was
        overlapping with the other merged dataframe.
    """
    columns = []
    for col in original_df.columns:
        if col in merged_df.columns:
            columns.append(col)
        elif col + suffix in merged_df.columns:
            columns.append(col + suffix)
        else:
            raise ValueError("Column not found: %s", col)
    return columns