MiniMax-AI/skills · warning · ValueError

Unsupported file format: {suffix}. Supported formats: .xlsx,

Error message

Unsupported file format: {suffix}. Supported formats: .xlsx, .xlsm, .csv, .tsv

What it means

The suffix matches none of .xlsx/.xlsm/.csv/.tsv/.xls, so detect_and_load() rejects it with ValueError listing the supported formats. The suffix is lowercased before comparison, so .XLSX is accepted but .ods/.numbers/.txt/.parquet are not.

Source

Thrown at skills/minimax-xlsx/scripts/xlsx_reader.py:84

                df = pd.read_csv(file_path, sep=sep, encoding=enc)
                df._reader_encoding = enc  # attach metadata (non-standard, for reporting)
                return {path.stem: df}
            except (UnicodeDecodeError, Exception) as e:
                last_error = e
                continue
        raise ValueError(
            f"Cannot decode {file_path}. Tried encodings: {encodings}. "
            f"Last error: {last_error}"
        )

    elif suffix == ".xls":
        raise ValueError(
            ".xls is a legacy binary format not supported by this tool. "
            "Please open the file in Excel and save as .xlsx, then retry."
        )

    else:
        raise ValueError(
            f"Unsupported file format: {suffix}. "
            "Supported formats: .xlsx, .xlsm, .csv, .tsv"
        )


# ---------------------------------------------------------------------------
# Structure discovery
# ---------------------------------------------------------------------------

def explore_structure(sheets: dict) -> dict:
    """
    Return a structured dict describing each sheet.
    Keys: sheet_name -> {shape, columns, dtypes, null_counts, preview}
    """
    result = {}
    for sheet_name, df in sheets.items():
        null_counts = df.isnull().sum()
        null_info = {

View on GitHub (pinned to 60aaae52bb)

Solutions

Convert/save to a supported format (.xlsx, .xlsm, .csv, or .tsv).
If the content is actually CSV, rename the extension to .csv.
For .ods, export to .xlsx from LibreOffice/Google Sheets.

Example fix

# before
python3 xlsx_reader.py data.ods   # ValueError: Unsupported file format: .ods

# after
libreoffice --headless --convert-to xlsx data.ods
python3 xlsx_reader.py data.xlsx

Defensive patterns

Strategy: validation

Validate before calling

from pathlib import Path
SUPPORTED = {'.xlsx', '.xlsm', '.csv', '.tsv'}
suf = Path(file_path).suffix.lower()
if suf not in SUPPORTED:
    raise ValueError(f'Unsupported file format: {suf}. Supported: {sorted(SUPPORTED)}')

Type guard

def is_supported_format(p) -> bool:
    return Path(p).suffix.lower() in {'.xlsx', '.xlsm', '.csv', '.tsv'}

Try / catch

try:
    sheets = detect_and_load(file_path)
except ValueError as e:
    if 'Unsupported file format' in str(e):
        print(f'Convert {file_path} to .xlsx/.csv/.tsv first.', file=sys.stderr)
    raise

Prevention

Validate the extension against the supported set before calling.
Normalize exports to .xlsx or .csv at the source.
Use Path.suffix.lower() so case variants are handled.

When it happens

Trigger: Passing .ods, .numbers, .txt, .parquet, .json, or any other unrecognized extension.

Common situations: Exporting from Google Sheets as .ods; passing a .txt assuming it reads as CSV; Mac Numbers export; a data file in a format the tool never claimed to support.

Related errors

AI-assisted analysis of MiniMax-AI/skills@60aaae52bb (2026-08-13). Data as JSON: /api/errors/bf26257743cca8e4. Report an issue: GitHub.