Ef_entsoo=en_ef_eurostat.new. merge (en_entsoo ratio, on=["Year", "fakecategory"]) always reports an error

[canfromnowon]

in # 5.7: Assign ratio for all old values per fake category (mapping one to many, using nep ratios)
Ef_entsoo=en_ef_eurostat.new. merge (en_entsoo ratio, on=["Year", "fakecategory"]) always reports an error

Traceback (most recent call last):
File "e:\Program Files\python310\lib\runpy.py", line 196, in _run_module_as_main
return _run_code(code, main_globals, None,
File "e:\Program Files\python310\lib\runpy.py", line 86, in run_code
exec(code, run_globals)
File "c:\Users\yg.vscode\extensions\ms-python.debugpy-2024.3.10611007-win32-x64\bundled\libs\debugpy_main.py", line 39, in
cli.main()
File "c:\Users\yg.vscode\extensions\ms-python.debugpy-2024.3.10611007-win32-x64\bundled\libs\debugpy/..\debugpy\server\cli.py", line 430, in main
run()
File "c:\Users\yg.vscode\extensions\ms-python.debugpy-2024.3.10611007-win32-x64\bundled\libs\debugpy/..\debugpy\server\cli.py", line 284, in run_file
runpy.run_path(target, run_name="main")
File "c:\Users\yg.vscode\extensions\ms-python.debugpy-2024.3.10611007-win32-x64\bundled\libs\debugpy_vendored\pydevd_pydevd_bundle\pydevd_runpy.py", line 321, in
run_path
return _run_module_code(code, init_globals, run_name,
File "c:\Users\yg.vscode\extensions\ms-python.debugpy-2024.3.10611007-win32-x64\bundled\libs\debugpy_vendored\pydevd_pydevd_bundle\pydevd_runpy.py", line 135, in
_run_module_code
_run_code(code, mod_globals, init_globals,
File "c:\Users\yg.vscode\extensions\ms-python.debugpy-2024.3.10611007-win32-x64\bundled\libs\debugpy_vendored\pydevd_pydevd_bundle\pydevd_runpy.py", line 124, in
_run_code
exec(code, run_globals)
File "E:\wos_Code\3_notebooks/main.py", line 2614, in
ef_pe_entsoe = en_ef_eurostat_new.merge(en_entsoe_ratio, on=["Year", "fakecategory"])
File "e:\Program Files\python310\lib\site-packages\pandas\core\frame.py", line 10832, in merge
return merge(
File "e:\Program Files\python310\lib\site-packages\pandas\core\reshape\merge.py", line 170, in merge
op = _MergeOperation(
File "e:\Program Files\python310\lib\site-packages\pandas\core\reshape\merge.py", line 794, in init
) = self._get_merge_keys()
File "e:\Program Files\python310\lib\site-packages\pandas\core\reshape\merge.py", line 1310, in _get_merge_keys
left_keys.append(left._get_label_or_level_values(lk))
File "e:\Program Files\python310\lib\site-packages\pandas\core\generic.py", line 1906, in _get_label_or_level_values
self._check_label_or_level_ambiguity(key, axis=axis)
File "e:\Program Files\python310\lib\site-packages\pandas\core\generic.py", line 1868, in _check_label_or_level_ambiguity
raise ValueError(msg)
ValueError: 'Year' is both an index level and a column label, which is ambiguous.

The data is from 2019_1 AggregatedGenerationPerType_16.1. B-C.csv to 2022 12 AggregatedGenerationPerType_16.1. B-C.csv