Evals / tables / Format conversion

Parse a European CSV

ventas.csv came from a Spanish Excel. Convert it to ventas.json as an array of objects.

normaledgemessydeft sheet convert

The task

The reference answer shows the job can be done with deft. It is not an agent run.

deft sheet convert ventas.csv -o ventas.json

Input

ventas.csv 114 B
producto;cantidad;precio;región
Café;12;3,50;Península
Té verde;7;2,25;Canarias
Azúcar;30;1,10;Península

Reference output

ventas.json 310 B
[
  {
    "producto": "Café",
    "cantidad": 12,
    "precio": 3.5,
    "región": "Península"
  },
  {
    "producto": "Té verde",
    "cantidad": 7,
    "precio": 2.25,
    "región": "Canarias"
  },
  {
    "producto": "Azúcar",
    "cantidad": 30,
    "precio": 1.1,
    "región": "Península"
  }
]
How a result is judged (1 check)
  • json_rows: file = "ventas.json", rows = 3, keys = ["producto", "cantidad", "región"]

Runs

CodexWithout deftPassed2026-11-07

Time
12s
New tokens
6.0k
Total input
40.6k
Output tokens
0.4k
Commands
2
Failed
0

Trace

  1. I’ll inspect the CSV’s encoding, delimiter, and headers, then write `ventas.json` in the current directory.

  2. ls -la && file ventas.csv && python3 - <<'PY' from pathlib import Path p=Path('ventas.csv') b=p.read_bytes() print('bytes',len(b),'prefix',repr(b[:200])) PY
    output
    total 8
drwxr-xr-x@    3 user  staff     96 Nov  6 17:26 .
drwx------@ 1750 user  staff  56000 Nov  6 17:26 ..
-rw-r--r--@    1 user  staff    114 Nov  5 18:26 ventas.csv
ventas.csv: Unicode text, UTF-8 (with BOM) text
bytes 114 prefix b'\xef\xbb\xbfproducto;cantidad;precio;regi\xc3\xb3n\nCaf\xc3\xa9;12;3,50;Pen\xc3\xadnsula\nT\xc3\xa9 verde;7;2,25;Canarias\nAz\xc3\xbacar;30;1,10;Pen\xc3\xadnsula\n'
  3. python3 - <<'PY' import csv, json from pathlib import Path with Path('ventas.csv').open(encoding='utf-8-sig', newline='') as f: rows = list(csv.DictReader(f, delimiter=';')) for row in rows: row['cantidad'] = int(row['cantidad']) row['precio'] = float(row['precio'].replace(',', '.')) Path('ventas.json').write_text(json.dumps(rows, ensure_ascii=False, indent=2) + '\\n', encoding='utf-8') PY cat ventas.json
    output
    [
  {
    "producto": "Café",
    "cantidad": 12,
    "precio": 3.5,
    "región": "Península"
  },
  {
    "producto": "Té verde",
    "cantidad": 7,
    "precio": 2.25,
    "región": "Canarias"
  },
  {
    "producto": "Azúcar",
    "cantidad": 30,
    "precio": 1.1,
    "región": "Península"
  }
]

  4. Created [ventas.json](ventas.json) as an array of objects, with Spanish headers and text preserved, and quantity and price converted to numbers.

Output

ventas.json 310 B
[
  {
    "producto": "Café",
    "cantidad": 12,
    "precio": 3.5,
    "región": "Península"
  },
  {
    "producto": "Té verde",
    "cantidad": 7,
    "precio": 2.25,
    "región": "Canarias"
  },
  {
    "producto": "Azúcar",
    "cantidad": 30,
    "precio": 1.1,
    "región": "Península"
  }
]

CodexWith deft, skill installedPassedRead the skillUsed deft2026-11-07

Time
17s
New tokens
5.7k
Total input
72.8k
Output tokens
0.6k
Commands
4
Failed
1

Trace

  1. I’ll inspect `ventas.csv` and its encoding and delimiters, then write the converted array to `ventas.json` in the current directory.

  2. cat .agents/skills/deft/SKILL.md && deft find (exit 2)
    output
    ---
name: deft
description: "Use deft first for any simple, direct operation on local files, whatever the type: convert, read, extract, edit, compress, merge, split, compare or inspect. Try it before writing a script or one-liner. If unsure, run deft find; if it says no command does this, use another tool. Not for programming work: to read, write or change source code, skip it."
---

# deft

One local command for file jobs. Prefer it over writing Python or shell scripts.

Syntax: `deft <group> <command> [inputs] [-o output] [--options]`

Groups:
- `pdf`: Merge, split, compress, encrypt, forms, OCR, compare, convert
- `image`: Resize, crop, convert, compress, filters, montage, OCR
- `video`: Trim, crop, speed, convert, compress, GIF, frames (ffmpeg)
- `audio`: Convert, trim, merge, fade, speed, tag, normalize (ffmpeg)
- `doc`: Word/ODT/RTF: to text, Markdown, HTML, PDF; find and replace
- `slides`: PowerPoint: extract text, Markdown outline, PDF handout
- `data`: JSON/YAML/TOML/XML: convert, query with jq syntax, merge, diff
- `sheet`: Excel/CSV/ODS tables: filter, sort, join, pivot, convert
- `md`: Markdown to PDF, HTML, Word, EPUB; table of contents
- `html`: HTML to Markdown, text, Word, PDF; screenshots
- `epub`: E-books: info, to text, Markdown and PDF
- `email`: EML files: headers, text, attachments
- `contact`: VCF address books: to and from CSV
- `calendar`: ICS calendars: to and from CSV
- `gps`: GPX and KML tracks: convert, distance and time
- `youtube`: Info, downlo
… 917 more characters

  3. I’m using the `deft` file-conversion tool first, as its local file workflow recommends. I’ll check its CSV conversion options and the file’s structure before creating the JSON.

  4. deft find "convert CSV to JSON" && deft sheet
    output
    data convert   data -> data    Change format: --to json|yaml|toml|xml|jsonl
sheet convert  sheet -> sheet  Change format: --to csv|xlsx|json
deft sheet - commands (input -> output)
  info       sheet -> report           Sheet names, rows, columns
  convert    sheet -> sheet            Change format: --to csv|xlsx|json
  dedupe     sheet -> sheet            Drop repeated rows, by whole row or --columns
  extract    sheet -> sheet            Take a sheet or range: --sheet, --range A1:D20
  filter     sheet -> sheet            Keep matching rows: --where "age > 30 and city = 'Oslo'"
  from-pdf   pdf -> sheet              All text as one table [beta]
  group      sheet -> sheet            Group and total: --columns city --values sales --agg sum
  join       sheet... -> sheet         Join two tables on a key: --on id --how left
  merge      sheet... -> sheet         Stack tables; a shared header is kept once
  pivot      sheet -> sheet            Pivot table: --rows city --columns year --values sales
  query      sheet|sqlite... -> sheet  Run SQL over tables or a SQLite file: --sql 'select ...'
  select     sheet -> sheet            Keep, reorder or --drop columns
  sort       sheet -> sheet            Sort rows: --columns age,name --descending
  split      sheet -> sheet...         Split up: --sheets, --columns city or --every 1000
  stats      sheet -> report           Per-column counts, empties, min, max, mean, sum
  to-md      sheet -> md               Markdown table (first ro
… 111 more characters
  5. ls -l ventas.csv && file ventas.csv && deft sheet info ventas.csv && deft sheet convert --help
    output
    -rw-r--r--@ 1 user  staff  114 Nov  5 18:26 ventas.csv
ventas.csv: Unicode text, UTF-8 (with BOM) text
ok sheet.info ventas.csv  ventas: 4 rows x 4 columns
sheets=[{"name":"ventas","rows":4,"columns":4}]
deft sheet convert - Change format: --to csv|xlsx|json
Same as: deft convert

Usage: deft sheet convert <sheet>... [-o <sheet|dir>] [options]
In: sheet (each handled separately)   Out: sheet (default <name>.<ext>)
JSON is an array of objects keyed by the first row.

Options:
  --to <csv|xlsx|json>         Target format (or give -o name.ext)
  --sheet <text>               Sheet name or number (default: first)
Common: -o --force --dry-run --json -j   (deft help common)

Examples:
  deft sheet convert people.csv --to xlsx -o table.xlsx
  deft sheet convert people.xlsx --to json -o people.json

Result fields: rows, columns
  6. deft sheet convert ventas.csv --to json -o ventas.json && cat ventas.json
    output
    ok sheet.convert ventas.csv -> ventas.json  4 rows x 4 columns  0.00s
[
  {
    "producto": "Café",
    "cantidad": 12,
    "precio": "3,50",
    "región": "Península"
  },
  {
    "producto": "Té verde",
    "cantidad": 7,
    "precio": "2,25",
    "región": "Canarias"
  },
  {
    "producto": "Azúcar",
    "cantidad": 30,
    "precio": "1,10",
    "región": "Península"
  }
]

  7. Created [ventas.json](ventas.json) as an array of objects, preserving the Spanish headers, accents, and comma-formatted prices. It contains 3 data rows.

Output

ventas.json 318 B
[
  {
    "producto": "Café",
    "cantidad": 12,
    "precio": "3,50",
    "región": "Península"
  },
  {
    "producto": "Té verde",
    "cantidad": 7,
    "precio": "2,25",
    "región": "Canarias"
  },
  {
    "producto": "Azúcar",
    "cantidad": 30,
    "precio": "1,10",
    "región": "Península"
  }
]

CodexWith deft, skill as AGENTS.mdPassed2026-11-05

Time
12s
New tokens
10.5k
Total input
61.6k
Output tokens
0.3k
Commands
3
Failed
0

Trace

  1. I’ll inspect the CSV’s delimiter and encoding, then convert it with the `deft` sheet tools and check the resulting JSON structure.

  2. pwd && rg --files -g 'ventas.csv' -g 'ventas.json' -g 'AGENTS.md' && deft sheet
    output
    AGENTS.md
ventas.csv
deft sheet - commands (input -> output)
  info     sheet -> report    Sheet names, rows, columns
  convert  sheet -> sheet     Change format: --to csv|xlsx|json
  extract  sheet -> sheet     Take a sheet or range: --sheet, --range A1:D20
  merge    sheet... -> sheet  Stack tables; a shared header is kept once
  to-md    sheet -> md        Markdown table (first row is the header)
More: deft sheet <command> --help
  3. deft sheet convert --help && file ventas.csv && python3 -c 'from pathlib import Path; p=Path(\"ventas.csv\"); b=p.read_bytes(); print(repr(b[:500]))'
    output
    deft sheet convert - Change format: --to csv|xlsx|json
Same as: deft convert

Usage: deft sheet convert <sheet>... [-o <sheet|dir>] [options]
In: sheet (each handled separately)   Out: sheet (default <name>.<ext>)
JSON is an array of objects keyed by the first row.

Options:
  --to <csv|xlsx|json>         Target format (or give -o name.ext)
  --sheet <text>               Sheet name or number (default: first)
Common: -o --force --dry-run --json -j   (deft help common)

Examples:
  deft sheet convert people.csv --to xlsx -o table.xlsx
  deft sheet convert people.xlsx --to json -o people.json

Result fields: rows, columns
ventas.csv: Unicode text, UTF-8 (with BOM) text
b'\xef\xbb\xbfproducto;cantidad;precio;regi\xc3\xb3n\nCaf\xc3\xa9;12;3,50;Pen\xc3\xadnsula\nT\xc3\xa9 verde;7;2,25;Canarias\nAz\xc3\xbacar;30;1,10;Pen\xc3\xadnsula\n'

  4. The file is UTF-8 with a BOM and uses semicolons plus decimal commas, typical Spanish Excel CSV conventions. I’m converting it while preserving values as written in the table.

  5. deft sheet convert ventas.csv --to json -o ventas.json && cat ventas.json
    output
    ok sheet.convert ventas.csv -> ventas.json  4 rows x 4 columns  0.00s
[
  {
    "cantidad": 12,
    "precio": "3,50",
    "producto": "Café",
    "región": "Península"
  },
  {
    "cantidad": 7,
    "precio": "2,25",
    "producto": "Té verde",
    "región": "Canarias"
  },
  {
    "cantidad": 30,
    "precio": "1,10",
    "producto": "Azúcar",
    "región": "Península"
  }
]

  6. Created [ventas.json](ventas.json) as an array of 3 objects. Spanish text and decimal commas are preserved.

Output

Its files were not kept in this run. The last line of the trace is its own report.

Claude Opus 5.5Without deftPassed2026-11-07

Time
15s
New tokens
9.7k
Total input
43.0k
Output tokens
0.8k
Commands
0
Failed
0

Trace

    Output

    ventas.json 310 B
    [
  {
    "producto": "Café",
    "cantidad": 12,
    "precio": 3.5,
    "región": "Península"
  },
  {
    "producto": "Té verde",
    "cantidad": 7,
    "precio": 2.25,
    "región": "Canarias"
  },
  {
    "producto": "Azúcar",
    "cantidad": 30,
    "precio": 1.1,
    "región": "Península"
  }
]

    Claude Opus 5.5With deft, skill installedPassedRead the skillUsed deft2026-11-07

    Time
    13s
    New tokens
    11.2k
    Total input
    77.4k
    Output tokens
    0.9k
    Commands
    0
    Failed
    0

    Trace

      Output

      .claude/skills/deft/SKILL.md 2.1 KB
      ---
name: deft
description: "Use deft first for any simple, direct operation on local files, whatever the type: convert, read, extract, edit, compress, merge, split, compare or inspect. Try it before writing a script or one-liner. If unsure, run deft find; if it says no command does this, use another tool. Not for programming work: to read, write or change source code, skip it."
---

# deft

One local command for file jobs. Prefer it over writing Python or shell scripts.

Syntax: `deft <group> <command> [inputs] [-o output] [--options]`

Groups:
- `pdf`: Merge, split, compress, encrypt, forms, OCR, compare, convert
- `image`: Resize, crop, convert, compress, adjust, montage, OCR
- `video`: Trim, merge, convert, compress, subtitles, GIF, frames (ffmpeg)
- `audio`: Convert, trim, normalize, denoise, cut silence (ffmpeg)
- `doc`: Word/ODT/RTF: to text, Markdown, HTML, PDF; find and replace
- `slides`: PowerPoint: extract text, Markdown outline
- `sheet`: Excel/CSV/ODS tables: SQL query, pivot, merge, split, convert
- `json`: JSON: convert, format, merge, diff, validate
- `toml`: TOML: convert, format, merge, diff, validate
- `xml`: XML: convert, format, merge, diff, validate
- `yaml`: YAML: convert, format, merge, diff, validate
- `md`: Markdown to PDF, HTML, Word, EPUB; table of contents
- `html`: HTML to Markdown, text, Word and PDF
- `epub`: E-books: info, to text, Markdown and PDF
- `gps`: GPX and KML tracks: convert, distance and time
- `qr`: Create QR codes and barcodes; read QR codes

How to use it:
1. Run `deft <group>` to list commands, or `deft find "<what you want>"` to search. If it says `no command does this`, use another tool.
2. Run `deft <group> <command> --help` for options and examples.
3. `deft convert <in> -o <out.ext>` converts between formats by extension.
4. Results are one line starting with `ok`, `partial` or `error`; add `--json` to parse them. Errors include a `hint:` with the fix.

Inputs are never overwritten; pass `--force` or `--in-place` to allow it. Globs and directories work as inputs; several inputs run in parallel.

If `deft` is not installed, ask the user, then follow https://github.com/firstprayer/deft/blob/main/docs/INSTALL.md
      ventas.json 310 B
      [
  {
    "producto": "Café",
    "cantidad": 12,
    "precio": 3.5,
    "región": "Península"
  },
  {
    "producto": "Té verde",
    "cantidad": 7,
    "precio": 2.25,
    "región": "Canarias"
  },
  {
    "producto": "Azúcar",
    "cantidad": 30,
    "precio": 1.1,
    "región": "Península"
  }
]

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