Text File Concatenator

A Python application that combines multiple plain-text files into a single file. Useful for composing prompts for LLMs. Features both GUI and command-line interfaces.

Features

• Two modes:
  • Concatenate all allowed plain-text files in a folder (with natural sorting)
  • Select specific files and arrange them in custom order
• Clear output: Each file's content is labeled with its filename
• UTF-8 support for international characters
• Error handling: Skips unreadable files and continues processing

Installation

# Install required dependency
pip install natsort

Usage

GUI Mode

Launch without arguments:

python concatenator.py

Folder Mode: Select a folder to concatenate all allowed plain-text files in natural order (e.g., file1, file2, file10).

File Selection Mode: Pick specific files and arrange them in custom order. You can:

• Reorder files manually using the Move Up/Down buttons
• Sort all files naturally using the Sort button
• Remove selected files or clear all

Import file list: In File Selection Mode, click "Add From List..." to import file paths from a text file. The file should contain one path per line. Supported:

• Blank lines and comment lines starting with # or ;
• Paths can be wrapped in single or double quotes
• Relative paths (resolved relative to the list file’s location)
• Environment variables and ~ expansion
• Only allowed plain-text types are added; duplicates are skipped; missing or not-allowed entries are reported in a summary dialog.

Example list file (example_list.txt):

# One path per line (comments and blanks allowed)
"test file 1.txt"
test file 2.txt
; From subfolder (relative to this file)
Test folder\test file 4.txt

Allowed file types

The app includes a static allow-list of common plain-text file types. A file is included if:

• Its extension is in the allow-list, or
• It matches a special filename (case-insensitive where applicable)

Extensions: .txt, .md, .markdown, .rst, .html, .htm, .xml, .csv, .tsv, .ini, .cfg, .conf, .properties, .env, .json, .yaml, .yml, .toml, .py, .js, .jsx, .ts, .tsx, .java, .c, .cpp, .h, .hpp, .cs, .go, .rb, .php, .swift, .kt, .sh, .bash, .zsh, .fish, .ps1, .bat, .sql, .pl, .lua, .r, .scala, .clj, .groovy, .dart, .css, .scss, .less

Special filenames: LICENSE, MAKEFILE, Makefile, Dockerfile, .editorconfig, .gitattributes, .gitignore, .dockerignore

Note: .ipynb and any other types not listed above are excluded.

CLI Mode

# Basic usage
python concatenator.py <folder_path> [output_path]

# Example
python concatenator.py /path/to/folder output.txt

Output Format

--- File: document1.txt ---

[Content of document1.txt]


--- File: document2.txt ---

[Content of document2.txt]

Requirements

• Python 3.6+
• tkinter (included with Python)
• natsort package

Troubleshooting

No GUI appears: Ensure tkinter is installed (comes with most Python installations)

Import error: Install natsort with pip install natsort

Unicode errors: Ensure your text files are UTF-8 encoded

License

Public domain - free to use and modify.