decx

Automated PowerPoint report generation from Excel data via COM.

decx reads data from Excel workbooks and updates linked OLE objects, tables, delta indicators, color coding, and charts in PowerPoint presentations — all driven from the command line.

Requirements

• Windows (COM automation requires Windows)
• Microsoft PowerPoint (installed and licensed)
• Microsoft Excel (installed and licensed)
• Python 3.11+

Installation

uv add decx

Or with pip:

pip install decx

Usage

decx is also available as dx for brevity — all examples below work with either.

Update presentations

# Single presentation — auto-detects linked Excel from OLE links
decx update report.pptx

# Explicitly specify Excel file
decx update report.pptx --excel data.xlsx

# Open file picker to choose Excel file
decx update report.pptx --pick

# Save output to a specific file (instead of modifying in-place)
decx update report.pptx --excel data.xlsx -o updated_report.pptx

# Save output to a directory
decx update report.pptx --excel data.xlsx -o output/

# Batch mode with explicit pptx:xlsx pairs
decx update --pair "us.pptx:us_data.xlsx" --pair "mx.pptx:mx_data.xlsx"

# Batch mode with output directory
decx update --pair "us.pptx:us.xlsx" --pair "mx.pptx:mx.xlsx" -o output/

# Run only specific steps
decx update report.pptx --only tables --only deltas
decx update report.pptx --excel data.xlsx --only links --only tables

# Skip specific steps
decx update report.pptx --excel data.xlsx --skip-links --skip-charts

# Override config values
decx update report.pptx --excel data.xlsx --set ccst.positive_prefix=""

# Verbose output for debugging
decx update report.pptx --excel data.xlsx --verbose

The -o/--output flag controls where results are written:

• -o result.pptx — write to a specific file (single-file mode only)
• -o output/ — write to a directory (works with batch mode too)
• omitted — modify the source file in-place

After processing, decx update prints a summary table per file and a grand total:

report.pptx <- data.xlsx (19.38s)
+--------------+-------+
| Step         | Count |
+--------------+-------+
| Links        |    86 |
| Tables       |    86 |
| Deltas       |     0 |
| Color coding |     0 |
| Charts       |   100 |
+--------------+-------+

All done! 1 file(s) in 19.38s
+--------------+-------+
| Step         | Total |
+--------------+-------+
| Links        |    86 |
| Tables       |    86 |
| Deltas       |     0 |
| Color coding |     0 |
| Charts       |   100 |
+--------------+-------+

Inspect a presentation

decx info report.pptx

Sample output:

Presentation
+----------+----------------------------------------+
| File     | report.pptx                            |
| Slides   | 30                                     |
+----------+----------------------------------------+

OLE Links
+-------------------------------------------+-------+
| Source File                               | Count |
+-------------------------------------------+-------+
| C:\data\tracking_Argentina.xlsx           |    86 |
| Total                                     |    86 |
+-------------------------------------------+-------+

Charts
+-------------------------------------------+-------+
| Type                                      | Count |
+-------------------------------------------+-------+
| Linked                                    |   100 |
| Unlinked                                  |     0 |
+-------------------------------------------+-------+

Special Shapes
+-------------------------------------------+-------+
| Type                                      | Count |
+-------------------------------------------+-------+
| ntbl_ (normal tables)                     |    42 |
| htmp_ (heatmap tables)                    |     3 |
| trns_ (transposed tables)                 |     2 |
| delt_ (delta indicators)                  |     8 |
| _ccst (color-coded)                       |     5 |
+-------------------------------------------+-------+

Delta Templates (Slide 1)
+-------------------------------------------+-------+
| Shape Name                                | Found |
+-------------------------------------------+-------+
| tmpl_delta_pos                            |   v   |
| tmpl_delta_neg                            |   v   |
| tmpl_delta_none                           |   v   |
+-------------------------------------------+-------+

Version

decx --version

CLI Reference

decx --version                  Show version and exit
decx --help                     Show help

decx update [FILES] [OPTIONS]   Run the update pipeline
  FILES                         One or more .pptx files (glob patterns OK)
  -e, --excel PATH              Excel data file (auto-detected from OLE links if omitted)
  -p, --pick                    Open file picker to select Excel file
  --pair PPT:XLSX               Explicit pptx:xlsx pair (repeatable)
  -o, --output PATH             Output file (.pptx) or directory
  --only STEP                   Run only specified step(s) (repeatable)
                                Valid: links, tables, deltas, coloring, charts
  --skip-links                  Skip OLE re-linking
  --skip-deltas                 Skip delta indicator updates
  --skip-coloring               Skip _ccst color coding
  --skip-charts                 Skip chart link updates
  -v, --verbose                 Debug logging
  --set KEY=VALUE               Override config value (repeatable, dot notation)

decx info FILE                  Inspect a .pptx file (read-only, no Excel needed)

decx config                     Show all available --set keys and defaults

decx steps                      Show all pipeline steps for use with --only

decx run RUNFILE [-v] [--check] Execute a Python runfile for batch processing

decx check FILE [-e EXCEL] [-v] Validate PPT values against Excel source data

decx diff A.pptx B.pptx [-v]   Compare two PPTX files and show value differences

decx clean [-f]                 Kill all PowerPoint and Excel processes

Configuration

decx ships with sensible defaults. Use --set to override values, or run decx config to see all available keys.

Any config value can also be overridden from the CLI with --set:

decx update report.pptx -e data.xlsx --set ccst.positive_prefix="" --set links.set_manual=false

Available --set keys

Runfiles

For batch processing multiple presentations (e.g. different regions or data sets), define all jobs in a Python runfile and execute with decx run:

decx run batch.py
decx run batch.py -v    # verbose

A runfile is a plain .py file with module-level variables. All paths resolve relative to the runfile's directory.

Single template

# batch.py

jobs = {
    "templates/report_template.pptx": {
        "group_a": "data/dataset_a.xlsx",
        "group_b": "data/dataset_b.xlsx",
        "group_c": "data/dataset_c.xlsx",
    },
}

default_output = "output/"
# -> output/group_a.pptx, output/group_b.pptx, output/group_c.pptx

Multiple templates

# batch.py

jobs = {
    "templates/report_type1.pptx": {
        "group_a": "data/dataset_a.xlsx",
        "group_b": "data/dataset_b.xlsx",
    },
    "templates/report_type2.pptx": {
        "group_c": "data/dataset_c.xlsx",
        "group_d": "data/dataset_d.xlsx",
    },
}

default_output = "output/report_2025_{name}.pptx"
# -> output/report_2025_group_a.pptx, output/report_2025_group_c.pptx, ...

steps = ["links", "tables", "deltas", "coloring", "charts"]

config = {
    "ccst.positive_prefix": "",
}

Per-job output override

Job values can be a string (excel path) or a dict with data + output:

jobs = {
    "templates/report_template.pptx": {
        "group_a": "data/dataset_a.xlsx",                           # -> uses default_output
        "group_b": {"data": "data/dataset_b.xlsx",                  # -> custom output path
                    "output": "special/group_b_final.pptx"},
    },
}

Runfile variables

Pipeline

1. Re-link OLE objects — point linked Excel objects to a new data file
2. Populate tables — read Excel ranges and write values into PowerPoint tables
3. Delta indicators — swap arrow shapes based on positive/negative values
4. Color coding — apply color rules to _ccst tables
5. Update charts — refresh linked chart data sources

Validation

After running the pipeline, use decx check to verify that PPT values match the Excel source data:

decx check report.pptx                    # check against current OLE links
decx check report.pptx --excel data.xlsx   # check against specific Excel file
decx check report.pptx -v                  # verbose — show every cell checked
decx check batch.py                        # check all jobs in a runfile
decx check batch.py -v                     # verbose runfile check
decx run batch.py --check                  # update + check after each job

decx check validates three categories:

Output includes a summary table with PASS/FAIL per category, and a mismatch details table with exact cell references for quick lookup:

┏━━━━━━━━┳━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━┳━━━━━━━━┓
┃ Check  ┃        Checked ┃ Mismatches ┃ Status ┃
┡━━━━━━━━╇━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━╇━━━━━━━━┩
│ Tables │            147 │          0 │  PASS  │
│ Deltas │              6 │          0 │  PASS  │
│ Charts │ 100 (214 series)│          0 │  PASS  │
└────────┴────────────────┴────────────┴────────┘

Exit code is 0 if all checks pass, 1 if any mismatches — useful for scripts and CI.

Diff

Compare two PPTX files to see exactly what values differ — useful for verifying updates or spotting regressions:

decx diff before.pptx after.pptx
decx diff template.pptx output/argentina.pptx

Compares table cell text, delta sign states, and chart series values. Read-only, no Excel needed. Exit code 1 if differences found.

Benchmark

Reference benchmarks on a 30-slide presentation with 86 OLE objects and 100 charts. Actual speed varies by machine, file size, and disk speed.

Batch processing 3 country reports: ~60s total.

Note: OLE visual thumbnails are not refreshed during update (they show cached images). This is intentional — refreshing each OLE visual adds ~4s per object for remote files and provides no value since OLE objects are hidden behind native PowerPoint tables. Tables, charts, and delta indicators all receive fresh data directly.

License

MIT

Repository

https://github.com/albertxli/decx