[BUG] Panel does not honor expand=False when it contains Columns

[andrewwjensen]

• I've checked docs and closed issues for possible solutions.
• I can't find my issue in the FAQ.

Describe the bug

The Panel object has an optional argument expand. When this is True (the default), the panel takes up the entire terminal width. When set to False, the panel shrinks to the width of the content inside the panel. This works most of the time, but fails when the Panel contains a Columns object. In this case, the Panel takes the whole terminal width with excess space on the right, even if expand=False is used.

A simple example that reproduces the issuse:

import rich
from rich.columns import Columns
from rich.panel import Panel

columns = Columns(['c1', 'c2'])
rich.print(Panel(columns, expand=False))
rich.print(Panel('this has expand=True', expand=True))
rich.print(Panel('this has expand=False', expand=False))

I've included two extra lines to show how it should work normally. Here is a screenshot of the output of the above program.

Platform

Click to expand

What platform (Win/Linux/Mac) are you running on? What terminal software are you using?
macOS Sequoia 15.6

I may ask you to copy and paste the output of the following commands. It may save some time if you do it now.

If you're using Rich in a terminal:

python -m rich.diagnose
pip freeze | grep rich

❯ python -m rich.diagnose
╭─────────────────── <class 'rich.console.Console'> ───────────────────╮
│ A high level console interface.                                      │
│                                                                      │
│ ╭──────────────────────────────────────────────────────────────────╮ │
│ │ <console width=72 ColorSystem.TRUECOLOR>                         │ │
│ ╰──────────────────────────────────────────────────────────────────╯ │
│                                                                      │
│     color_system = 'truecolor'                                       │
│         encoding = 'utf-8'                                           │
│             file = <_io.TextIOWrapper name='<stdout>' mode='w'       │
│                    encoding='utf-8'>                                 │
│           height = 76                                                │
│    is_alt_screen = False                                             │
│ is_dumb_terminal = False                                             │
│   is_interactive = True                                              │
│       is_jupyter = False                                             │
│      is_terminal = True                                              │
│   legacy_windows = False                                             │
│         no_color = False                                             │
│          options = ConsoleOptions(                                   │
│                        size=ConsoleDimensions(width=72, height=76),  │
│                        legacy_windows=False,                         │
│                        min_width=1,                                  │
│                        max_width=72,                                 │
│                        is_terminal=True,                             │
│                        encoding='utf-8',                             │
│                        max_height=76,                                │
│                        justify=None,                                 │
│                        overflow=None,                                │
│                        no_wrap=False,                                │
│                        highlight=None,                               │
│                        markup=None,                                  │
│                        height=None                                   │
│                    )                                                 │
│            quiet = False                                             │
│           record = False                                             │
│         safe_box = True                                              │
│             size = ConsoleDimensions(width=72, height=76)            │
│        soft_wrap = False                                             │
│           stderr = False                                             │
│            style = None                                              │
│         tab_size = 8                                                 │
│            width = 72                                                │
╰──────────────────────────────────────────────────────────────────────╯
╭─── <class 'rich._windows.WindowsConsoleFeatures'> ────╮
│ Windows features available.                           │
│                                                       │
│ ╭───────────────────────────────────────────────────╮ │
│ │ WindowsConsoleFeatures(vt=False, truecolor=False) │ │
│ ╰───────────────────────────────────────────────────╯ │
│                                                       │
│ truecolor = False                                     │
│        vt = False                                     │
╰───────────────────────────────────────────────────────╯
╭────── Environment Variables ───────╮
│ {                                  │
│     'CLICOLOR': None,              │
│     'COLORTERM': 'truecolor',      │
│     'COLUMNS': '72',               │
│     'JPY_PARENT_PID': None,        │
│     'JUPYTER_COLUMNS': None,       │
│     'JUPYTER_LINES': None,         │
│     'LINES': '76',                 │
│     'NO_COLOR': None,              │
│     'TERM_PROGRAM': 'iTerm.app',   │
│     'TERM': 'xterm-256color',      │
│     'TTY_COMPATIBLE': None,        │
│     'TTY_INTERACTIVE': None,       │
│     'VSCODE_VERBOSE_LOGGING': None │
│ }                                  │
╰────────────────────────────────────╯
platform="Darwin"
rich==14.1.0

If you're using Rich in a Jupyter Notebook, run the following snippet in a cell
and paste the output in your bug report.

from rich.diagnose import report
report()

[github-actions]

Thank you for your issue. Give us a little time to review it.

PS. You might want to check the FAQ if you haven't done so already.

Rich was created by Will McGugan. Consider sponsoring Will's work on Rich.

This is an automated reply, generated by FAQtory

[Stranger-Jie]

This is because Columns does not implement the __rich_measure__ method, which results in the width of the Columns object not being measured when it is printed, and the default terminal width is used instead. As a result, the expand is ineffective for the output of Columns.

[microy]

I confirm this bug.

And I confirm Pull Request #3823 works !!!