def combine_dfs(dfs, names, method):
if method == "<STR_LIT>":<EOL><INDENT>res = list()<EOL>for df, identifier in zip(dfs, names):<EOL><INDENT>df["<STR_LIT>"] = identifier<EOL>res.append(df)<EOL><DEDENT>return pd.concat(res, ignore_index=True)<EOL><DEDENT>elif method == "<STR_LIT>":<EOL><INDENT>return pd.concat(dfs, ignore_index=True)<EOL><DEDENT>
Combine dataframes.

    Combination is either done simple by just concatenating the DataFrames
    or performs tracking by adding the name of the dataset as a column.