Femto v0.0.3

Femto is a tiny, nano-style terminal text editor written in pure Python. It ships with zero runtime dependencies on POSIX system (standard-library curses only) and automatically pulls windows-curses on Windows.

Femto supports multi-buffer editing, soft line wrapping, syntax highlighting, regex search & replace, mouse support, and is fully Unicode (CJK/Emoji) aware.

Femto v0.0.3: Featuring the F1 help screen, stateful Python docstring highlighting, word-boundary wrapping, and multi-match search overlays.

Install

# From PyPI (Recommended)
pipx install femto-editor
# or
pip install femto-editor

# From source
git clone https://github.com/codewithzaqar/femto.git
cd femto
pip install .

After installation, the femto command is available globally.

Usage

femto [file ...]        # open one or multiple files
femto --line-numbers a.py x.py
femto --tab-size 2 --regex x.py
femto --version

Keybindings

Press F1 in normal editing mode to open read-only help. Use Up/Down, PgUp/PgDn, or Home/End to scroll; Esc or q returns to editing without changing the document. Bindings below are grouped by the context in which they work.

The tables and help share KEYBINDINGS in femto/help.py. When changing shortcuts, update that catalog and run python -m femto.help to regenerate the tables between the markers. The test suite checks that these tables stay in sync and exercises documented keys against the real input handlers. F1 is ignored in prompts and confirmations.

Help (editing only)

Key	Action
F1	Open read-only help; Esc or q returns to editing

Terminal (outside help)

Key	Action
Ctrl+C	Interrupt and exit without save confirmation

File and buffers (editing)

Key	Action
Ctrl+X	Exit; asks to save modified buffers
Ctrl+S	Save; Save As if unnamed
Ctrl+F / Ctrl+L	Next / previous buffer

Navigation (editing)

Key	Action
Arrows	Move cursor
Ctrl+Left / Ctrl+Right	Previous / next word
Shift+Left / Shift+Right	Previous / next word
Home / Ctrl+A	Line start
End / Ctrl+E	Line end
PgUp / PgDn	Move cursor one page up / down
Ctrl+T	Go to line

Editing

Key	Action
Enter	Insert newline
Tab	Insert indentation at cursor
Shift+Tab	Remove leading indentation from current line
Backspace / Ctrl+H	Delete before cursor; join at line start
Delete	Delete at cursor; join at line end
Ctrl+Z / Ctrl+Y	Undo / redo

Clipboard and selection (editing)

Key	Action
Ctrl+B	Set / clear selection mark; move cursor to select
Ctrl+K	Cut selection, or current line if selection is empty
Ctrl+P	Copy selection, or current line if selection is empty
Ctrl+U	Paste internal clipboard

Search and replace (editing)

Key	Action
Ctrl+W	Open search; Enter finds next (wraps at end of buffer)
Ctrl+\	Replace: search term, replacement, then confirmation

View and mouse (editing)

Key	Action
Ctrl+N	Toggle line numbers
Ctrl+D	Toggle mouse support
Mouse click	Move cursor to clicked position (mouse enabled)
Mouse wheel	Move cursor three lines up / down (mouse enabled)

Prompts (Save As, Search, Replace, Go To Line)

Key	Action
Enter	Confirm current prompt
Ctrl+G / Esc	Cancel prompt
Left / Right	Move prompt cursor
Home / End	Start / end of prompt text
Backspace / Ctrl+H	Delete before prompt cursor
Delete	Delete at prompt cursor

Search options (Search and Replace search prompts only)

Key	Action
Ctrl+O	Toggle case-insensitive search
Ctrl+R	Toggle regular expressions

Replace confirmation

Key	Action
Y / N / A	Replace current match / skip match / replace all
C / Ctrl+G / Esc	Cancel remaining replacements

Exit confirmation

Key	Action
Y / N	Save modified buffers and exit / exit without saving
C / Ctrl+G / Esc	Cancel exit

Help navigation (help only)

Key	Action
Esc / q	Close help and return to editing
Up / Down	Scroll one help row
PgUp / PgDn	Scroll one help page
Home / End	First / last help page

Configuration (~/.femtorc or ./.femtorc)

Femto is highly customizable via a simple key = value configuration file.

# Indentation
tab_size = 4

# Viewport
smooth_scroll_margin = 3
soft_wrap = true
show_line_numbers = false
syntax_highlight = true

# Search
ignore_case = false
regex_search = false

# Editing
auto_indent = true
system_clipboard = false

# Wrapping
wrap_at_word = true

# Input & I/O
mouse = false
make_backup = false
# auto keeps the ending detected on load (LF for new files); lf or crlf forces it
line_ending = auto
final_newline = true  # ensure POSIX trailing newline

Running the tests

Femto includes a comprehensive unittest regression suite that runs headlessely (no terminal required).

python -m unittest discover -s tests -v

Building a release

pip install build twine
python -m build          # creates dist/femto_editor-0.0.1-*.whl
python -m twine upload dist/* # publish to PyPI

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License

MIT - see LICENSE.