@transformer<EOL>def left_join(input, **params):
PARAM_COL_RIGHT = '<STR_LIT>'<EOL>PARAM_COL_LEFT = '<STR_LIT>'<EOL>PARAM_FIELD_JOIN = '<STR_LIT>'<EOL>right_df = pd.DataFrame.from_records(input[params.get(PARAM_COL_RIGHT)])<EOL>left_df = pd.DataFrame.from_records(input[params.get(PARAM_COL_LEFT)])<EOL>join_on = params.get(PARAM_FIELD_JOIN)<EOL>res = right_df.set_index(join_on, drop=False).join(left_df.set_index(join_on, drop=False), on=[join_on], rsuffix='<STR_LIT>')<EOL>return Converter.df2list(res)<EOL>
Left join transformation
:param input:
:param params:
:return: