Fast, dependency-free terminal tables — and optional packages for full terminal apps.
54 border styles · ANSI colours · cell merges · decimal alignment · width fitting · CSV / Markdown / HTML / Excel / LaTeX I/O · grids · 80+ terminal components · C-accelerated frames

flexablelib turns rows and columns into readable tables for terminals, logs, reports and docs. It has no runtime dependencies, ships prebuilt wheels with an optional C speed-up, and is covered by 4,500+ tests on Python 3.8 – 3.14 (Linux, Windows, macOS).

Since 3.3.0 the same library builds complete interactive terminal applications: keyboard focus, key bindings, dialogs, notifications, 80+ ready-made components (inputs, dates, tables, forms, menus, charts, dialogs) and optional C code that computes each interface frame. All of it is opt-in; pip install flexablelib stays a single dependency-free package.

Install

pip install flexablelib — the core: tables, cards, grids, widgets. No dependencies.

Quote the extras in shells that expand brackets: pip install "flexablelib[tui,components,speed]". Details: docs/INSTALL.md.

Terminal applications

examples/admin.py is a complete back-office app built only with flexablelib: AppShell (sidebar, top bar, pages), Stat cards, a braille LineChart, a Timeline, a DataTable bound to a FilterBar (estado:pagado total>5000), forms with validation, a command palette (Ctrl-K), dialogs and notifications. Run it with python examples/admin.py; --frame 120x36 --keys "tab,down,enter" prints a single frame instead (that is how these images are made).

Keyboard and focus — Tab, arrows, Enter, modal dialogs	Forms — required fields, validators, masks, notifications
Filter and sort — estado:pagado total>5000, keys 1–9 sort	Narrow terminals — the sidebar hides, cards reflow
Command palette and help	No colour — zero escape sequences, same layout

Components

flexablelib[components] adds 80+ components, each rendered at any width, in colour or plain text: the full list, what each does and its keys is in docs/COMPONENTS.md.

Inputs — text, password, numbers, money, masks, expressions, JSON, scanners, choices, colours, files	Dates and times — calendar, date, time, week, month, ranges, timer
Display — badges, alerts, code, Markdown, HTML, timelines, steps, stats, charts	Navigation — tabs, menus, sidebar, wizard, tree, command palette, app shell
Data — interactive table, filters, editable table, catalog, forms, login	Dialogs — modal, confirm, prompt, loading, popover
New in 3.6.0 — signature pad, stopwatch, a vertical stack that shares its height and follows the focus, focus shown without colour, forms that collect nested fields and editable tables, scanners that keep the code read, catalog cards with pictures, pictures downloaded with an Authorization header, a validation summary from a list of errors

Keyboard, mouse and accessibility

Since 3.4.0: docs/INPUT.md · docs/ACCESSIBILITY.md · docs/FOLIOS.md.

Every key detected — F1–F24, Ctrl/Alt/Shift/Super, paste, focus, mouse — examples/keys.py	Mouse in every component — click, wheel, drag
Focus visible without colour — text markers, not colour alone	High contrast — WCAG AAA text, checked by the tests
Colour-blind themes — deuteranopia, protanopia, tritanopia — simulated	Screen readers — linear text, roles, labels, announcements
ASCII and reduced motion — no Unicode, still spinners	Folios — IDs without thousands separators, money with them
One name per key — xterm, rxvt, Linux console, kitty, modifyOtherKeys, Windows	C acceleration — ASCII fallback and click zones

Pictures in the terminal

Since 3.5.0: docs/IMAGES.md — kitty, iTerm2, sixel, Unicode blocks, ASCII, then a link to the browser, then a warning. Real terminals under Xvfb.

kitty graphics protocol — detected, Unicode placeholders	iTerm2 inline images — WezTerm, iTerm2, VS Code, Konsole
sixel — xterm, foot, mlterm, Windows Terminal	Unicode blocks — half blocks, quadrants, sextants
Braille and ASCII — mono with NO_COLOR, ASCII without Unicode	Inside Grid, Card and App — the frame diff keeps working
Link to the browser — OSC 8, Enter or click opens it	No browser, no display — a warning, nothing opened
Redraws in kitty, xterm and WezTerm — ImageViewer in an App	C acceleration — resize, quantize, sixel, blocks

Speed

Every frame of an interface is re-laid out and diffed against the previous one; only changed lines are written. flexablelib[speed] moves the per-line work (measuring, cutting, padding, border junctions, the diff) to C: a full back-office screen at 160×48 takes 0.47 ms (2,100 fps) instead of 6.4 ms in pure Python. Results are identical with and without C — the test suite checks both on random input — and FLEXABLELIB_FRAMES=python switches the C code off. Method and numbers: docs/ACCELERATION.md.

30-second quickstart

The image at the top is the whole program. Numbers align on the decimal point, colours never break alignment, and the same table exports anywhere:

Feature gallery

Styles — 54 presets, from ascii_rows to borderless	Themes — table.apply_theme("ocean")
Text on borders — table.border_text("Production", where="top")	Cell merges — table.merge_cells(0, 0, last_row=1)
Zebra rows, footer, caption	Decimal alignment — floats and scientific notation

More: all 54 styles · wrapping and ellipsis overflow · per-column / per-cell colour and alignment · vertical alignment · paginate() · stream() for live rows · transpose() · nested tables · fit_terminal() · hide_columns · sort_by · Roman / custom index.

How it compares

A factual feature matrix from our survey of 89 table libraries. A dash means the feature was not found in that library's documentation during the survey, not a claim that it is impossible there.

rich is a full terminal-rendering toolkit (markup, live displays, progress bars) and tabulate covers many more markup dialects; pick flexablelib when you want a dependency-free, table-focused library with styling, merges and I/O in one place.

Production notes

• Zero runtime dependencies. Readers/writers that need a third-party package (pandas, openpyxl, lxml) are opt-in extras and imported lazily.
• Performance. Rendering 10,000 rows × 6 columns takes ~157 ms with the C extension (~172 ms pure Python), on par with prettytable, ~1.3× faster than tabulate and ~18× faster than rich's table. pandas to_string() is faster still (~85 ms). Full method and numbers: docs/BENCHMARKS.md.
• Wheels. Prebuilt for CPython 3.8 – 3.14 on Linux (manylinux, musllinux), Windows x64 and macOS arm64, for both flexablelib and flexablelib-speedups. Anywhere else it builds from source or falls back to pure Python — installation never fails for want of a compiler. from flexablelib.fast import implementation; implementation() tells you which backend is live.
• Colour safety. Escape sequences are emitted only to a TTY by default, never when NO_COLOR is set; FORCE_COLOR or table.use_colors = True overrides. Logs and files stay clean.
• Unicode. Widths are measured in terminal columns, so CJK, emoji and coloured text stay aligned.
• Windows. Box-drawing styles need a UTF-8 console (chcp 65001 or PYTHONUTF8=1; Windows Terminal is usually UTF-8 already). ASCII styles (ascii_rows, ascii_double_underline_rows, psql, markdown, …) work on any code page.
• Typed. Ships py.typed (PEP 561).
• Stability. flexablelib follows semantic versioning: within 3.x, public Table attributes and methods are not removed or renamed without a deprecation period; new features arrive in minor/patch releases and every release is listed in the CHANGELOG.
• Support. Bugs and requests: issues. Security reports: SECURITY.md. Contributions: CONTRIBUTING.md.

Windows console encoding

Box-drawing styles need a UTF-8 console: run chcp 65001 and set PYTHONUTF8=1 (PowerShell: $env:PYTHONUTF8=1). Windows Terminal is usually UTF-8 already. The terminal packages enable virtual-terminal output on Windows consoles themselves.

Guide

Usage

Creating a table is simple. An empty table has no data, so it only draws its frame; a table with columns but no rows — a query that came back empty — shows its headers rather than raising:

Data can be added as columns or rows, or alternating each one. Any untitled column is named automatically.

The table formats new lines and data types automatically, without trying to parse strings that could be converted to another type.

The Table class offers options for showing the index of each row, changing the style, hiding the headers, and more. See all styles here. The missing value aligns as if it were of the same type as the other data in the column, and the row and column counts ignore the index column (the internal counts include it):

Changed in 2.3.0: an explicit None is a missing cell, just like a padding gap or table.missing. It displays missing_value (blank by default), not the text "None". Use the string "None" if you want that literal text. This applies to printing, compose(), pagination, streaming, and transposition in every style.

Missing cells do not turn numeric columns into text: numeric alignment and the decimal axis are preserved, and overflow='wrap' does not split floats because a column contains None. Raw rows and exports still represent gaps as None; rendering Table(rows=table.rows) reproduces the same cells (copy headers and display settings too if you changed them).

See missing-cell semantics for migration details.

Colour

Colour the header, the borders, whole columns, whole rows, or individual cells. Specs accept names, attributes, 256-colour indexes and hex triples. color_rule receives the original value, so numeric comparisons work directly.

Colour is emitted only to a terminal by default, and never when NO_COLOR is set. FORCE_COLOR or table.use_colors = True overrides that. Because compose() returns a string you may send anywhere, the default errs toward not embedding escape sequences in something bound for a file.

Widths are measured in terminal columns, not characters, so coloured cells and CJK or emoji data stay aligned.

Reading and writing

Readers: Table.from_csv, from_html (standard library parser), from_dicts, from_markdown, from_pandas (flexablelib[pandas]) and from_excel (flexablelib[excel]). Writers: to_csv, to_markdown, to_html (one self-contained file with inline sorting, filtering and pagination that works offline), to_rst, to_asciidoc, to_latex, to_excel and to_records.

Since 2.2.0 every export writes the table as print(table) shows it: rows in sort_by order (with sort_reverse and callables), row_filter applied, hide_columns left out, and the text formats hold the formatted strings — float_format, int_format, leading_zeros, custom_format, strip_cells — without padding or colour. Empty cells are empty strings.

to_records() keeps the stored Python values (numbers stay numbers, gaps are None) in display order; to_records(formatted=True) gives the printed strings. to_excel() writes numbers as numbers and turns simple format specs (',d', '.2f', '.1%', '{:,.2f}'…) into the cell's Excel number format.

Text formats deliver everything as strings, and a column of strings is left-aligned. table.parse_str_numbers = True converts numeric-looking text so it aligns as numbers; the readers turn it on for you. Values with leading zeros are left alone, so '007' stays a string.

table.rows is a copy of the stored data, in insertion order and with None in empty cells (sorting, filtering and formats do not touch it), so editing it does not change the table. Use add_row and set_cell(row, column, value) instead (column is a position or a header; table.missing empties a cell).

Merging cells

Render a rectangular block as a single cell, across columns, down rows, or both. Coordinates are inclusive, zero-based, and ignore the index column.

A merge never widens the table — columns are still sized by their unmerged content — so text longer than its span is truncated.

Cards, grids, responsive tables and terminal layouts

Card draws one record in a frame, in any of the table styles. The title goes into the top border when the style draws one; field_columns=2 (or 'auto') lays the fields out as tiles and actions adds [ Action ] chips:

Cards take style_name, theme (the table themes), border_color, title_color, label_color, value_colors, color (a background for the whole card), zebra, panel and shadow.

table.render(width) makes a table responsive: the normal table when it fits, without its low-priority columns next, squeezed and wrapped after that, and one card per row when nothing else fits. width defaults to max_width, then the terminal width; responsive=True makes print(table) do the same.

Grid places cards, tables, text and other grids in columns that reflow with the width. Since 3.3.0 a cell can be pinned with row= and column=; empty slots are closed in bordered grids (fill_gaps=False keeps them open), and to_cards() carries merged cells into every card they cover.

A grid can size its columns (12, 'auto', '2fr', '30%', bounds, or one layout per width), span rows, share one border with proper junctions and a title per cell, and fill an exact height. Widgets — ProgressBar, Sparkline, BarChart, StatusBar, KeyHints, LogView, Text, Rule — drop into it, Screen pins a header and footer to the terminal's edges and Live redraws in place:

A whole dashboard with a sidebar, KPI cards, a coloured table with merges, bars, sparklines and a log: examples/dashboard.py (python examples/dashboard.py --live 10). More in docs/LAYOUT.md.

Notes

• A column named "i" does not collide with the index column (utils.IndexColumnTitle).
• Exponential numbers align on the decimal / exponent axis with the rest of the float column.
• Shrinking a float column drops decimals instead of chopping characters, so decimal alignment survives a terminal fit (#23).

Open work and the issue map: docs/ISSUES.md.

Project layout

• flexablelib/ — the core package (no runtime dependencies): table.py (the Table class), layout.py (Card, Grid, GridCell), _frames.py (frame primitives, C or Python), columns.py, cells.py, table_strings.py, style_compositions.py (the 54 styles, as data), text_width.py / fast.py (terminal-width measurement, C or Python), readers and writers.
• packages/tui/ — flexablelib-tui: widgets, Screen, Live, App, keyboard and mouse input, accessibility.
• packages/components/ — flexablelib-components: the terminal components.
• packages/speedups/ — flexablelib-speedups: the C frame code.
• examples/ — dashboard.py, admin.py, keys.py (live key detector).
• tests/ — the pytest suite; tools/ — benchmarks and generators; docs/ — guides and images.
• ARCHITECTURE.md — how it all fits together; style_examples.md — all 54 styles; package.json — the canonical version number.

See ARCHITECTURE.md for the rendering pipeline, how styles are defined, and how to add one.