Console API

For complete control over terminal formatting, Rich offers a Console class. Most applications will require a single Console instance, so you may want to create one at the module level or as an attribute of your top-level object. For example, you could add a file called “console.py” to your project:

from rich.console import Console
console = Console()

Then you can import the console from anywhere in your project like this:

from my_project.console import console

The console object handles the mechanics of generating ANSI escape sequences for color and style. It will auto-detect the capabilities of the terminal and convert colors if necessary.

Attributes

The console will auto-detect a number of properties required when rendering.

  • size is the current dimensions of the terminal (which may change if you resize the window).

  • encoding is the default encoding (typically “utf-8”).

  • is_terminal is a boolean that indicates if the Console instance is writing to a terminal or not.

  • color_system is a string containing the Console color system (see below).

Color systems

There are several “standards” for writing color to the terminal which are not all universally supported. Rich will auto-detect the appropriate color system, or you can set it manually by supplying a value for color_system to the Console constructor.

You can set color_system to one of the following values:

  • None Disables color entirely.

  • "auto" Will auto-detect the color system.

  • "standard" Can display 8 colors, with normal and bright variations, for 16 colors in total.

  • "256" Can display the 16 colors from “standard” plus a fixed palette of 240 colors.

  • "truecolor" Can display 16.7 million colors, which is likely all the colors your monitor can display.

  • "windows" Can display 8 colors in legacy Windows terminal. New Windows terminal can display “truecolor”.

Warning

Be careful when setting a color system, if you set a higher color system than your terminal supports, your text may be unreadable.

Printing

To write rich content to the terminal use the print() method. Rich will convert any object to a string via its (__str__) method and perform some simple syntax highlighting. It will also do pretty printing of any containers, such as dicts and lists. If you print a string it will render Console Markup. Here are some examples:

console.print([1, 2, 3])
console.print("[blue underline]Looks like a link")
console.print(locals())
console.print("FOO", style="white on blue")

You can also use print() to render objects that support the Console Protocol, which includes Rich’s built in objects such as Text, Table, and Syntax – or other custom objects.

Logging

The log() methods offers the same capabilities as print, but adds some features useful for debugging a running application. Logging writes the current time in a column to the left, and the file and line where the method was called to a column on the right. Here’s an example:

>>> console.log("Hello, World!")
[16:32:08] Hello, World!                                         <stdin>:1

To help with debugging, the log() method has a log_locals parameter. If you set this to True, Rich will display a table of local variables where the method was called.

Low level output

In additional to print() and log(), Rich has a out() method which provides a lower-level way of writing to the terminal. The out() method converts all the positional arguments to strings and won’t pretty print, word wrap, or apply markup to the output, but can apply a basic style and will optionally do highlighting.

Here’s an example:

>>> console.out("Locals", locals())

Rules

The rule() method will draw a horizontal line with an optional title, which is a good way of dividing your terminal output in to sections.

>>> console.rule("[bold red]Chapter 2")
─────────────────────────────── Chapter 2 ───────────────────────────────

The rule method also accepts a style parameter to set the style of the line, and an align parameter to align the title (“left”, “center”, or “right”).

Status

Rich can display a status message with a ‘spinner’ animation that won’t interfere with regular console output. Run the following command for a demo of this feature:

python -m rich.status

To display a status message, call status() with the status message (which may be a string, Text, or other renderable). The result is a context manager which starts and stop the status display around a block of code. Here’s an example:

with console.status("Working..."):
    do_work()

You can change the spinner animation via the spinner parameter:

with console.status("Monkeying around...", spinner="monkey"):
    do_work()

Run the following command to see the available choices for spinner:

python -m rich.spinner

Justify / Alignment

Both print and log support a justify argument which if set must be one of “default”, “left”, “right”, “center”, or “full”. If “left”, any text printed (or logged) will be left aligned, if “right” text will be aligned to the right of the terminal, if “center” the text will be centered, and if “full” the text will be lined up with both the left and right edges of the terminal (like printed text in a book).

The default for justify is "default" which will generally look the same as "left" but with a subtle difference. Left justify will pad the right of the text with spaces, while a default justify will not. You will only notice the difference if you set a background color with the style argument. The following example demonstrates the difference:

from rich.console import Console

console = Console(width=20)

style = "bold white on blue"
console.print("Rich", style=style)
console.print("Rich", style=style, justify="left")
console.print("Rich", style=style, justify="center")
console.print("Rich", style=style, justify="right")

This produces the following output:

Rich
Rich                
        Rich        
                Rich

Overflow

Overflow is what happens when text you print is larger than the available space. Overflow may occur if you print long ‘words’ such as URLs for instance, or if you have text inside a panel or table cell with restricted space.

You can specify how Rich should handle overflow with the overflow argument to print() which should be one of the following strings: “fold”, “crop”, “ellipsis”, or “ignore”. The default is “fold” which will put any excess characters on the following line, creating as many new lines as required to fit the text.

The “crop” method truncates the text at the end of the line, discarding any characters that would overflow.

The “ellipsis” method is similar to “crop”, but will insert an ellipsis character (“…”) at the end of any text that has been truncated.

The following code demonstrates the basic overflow methods:

from typing import List
from rich.console import Console, OverflowMethod

console = Console(width=14)
supercali = "supercalifragilisticexpialidocious"

overflow_methods: List[OverflowMethod] = ["fold", "crop", "ellipsis"]
for overflow in overflow_methods:
    console.rule(overflow)
    console.print(supercali, overflow=overflow, style="bold blue")
    console.print()

This produces the following output:

──── fold ────
supercalifragi
listicexpialid
ocious

──── crop ────
supercalifragi

── ellipsis ──
supercalifrag…

You can also set overflow to “ignore” which allows text to run on to the next line. In practice this will look the same as “crop” unless you also set crop=False when calling print().

Console style

The Console has a style attribute which you can use to apply a style to everything you print. By default style is None meaning no extra style is applied, but you can set it to any valid style. Here’s an example of a Console with a style attribute set:

from rich.console import Console
blue_console = Console(style="white on blue")
blue_console.print("I'm blue. Da ba dee da ba di.")

Soft Wrapping

Rich word wraps text you print by inserting line breaks. You can disable this behavior by setting soft_wrap=True when calling print(). With soft wrapping enabled any text that doesn’t fit will run on to the following line(s), just like the builtin print.

Cropping

The print() method has a boolean crop argument. The default value for crop is True which tells Rich to crop any content that would otherwise run on to the next line. You generally don’t need to think about cropping, as Rich will resize content to fit within the available width.

Note

Cropping is automatically disabled if you print with soft_wrap=True.

Input

The console class has an input() which works in the same way as Python’s builtin input() method, but can use anything that Rich can print as a prompt. For example, here’s a colorful prompt with an emoji:

from rich.console import Console
console = Console()
console.input("What is [i]your[/i] [bold red]name[/]? :smiley: ")

Exporting

The Console class can export anything written to it as either text or html. To enable exporting, first set record=True on the constructor. This tells Rich to save a copy of any data you print() or log(). Here’s an example:

from rich.console import Console
console = Console(record=True)

After you have written content, you can call export_text() or export_html() to get the console output as a string. You can also call save_text() or save_html() to write the contents directly to disk.

For examples of the html output generated by Rich Console, see Standard Colors.

Error console

The Console object will write to sys.stdout by default (so that you see output in the terminal). If you construct the Console with stderr=True Rich will write to sys.stderr. You may want to use this to create an error console so you can split error messages from regular output. Here’s an example:

from rich.console import Console
error_console = Console(stderr=True)

You might also want to set the style parameter on the Console to make error messages visually distinct. Here’s how you might do that:

error_console = Console(stderr=True, style="bold red")

File output

You can also tell the Console object to write to a file by setting the file argument on the constructor – which should be a file-like object opened for writing text. You could use this to write to a file without the output ever appearing on the terminal. Here’s an example:

import sys
from rich.console import Console
from datetime import datetime

with open("report.txt", "wt") as report_file:
    console = Console(file=report_file)
    console.rule(f"Report Generated {datetime.now().ctime()}")

Note that when writing to a file you may want to explicitly the width argument if you don’t want to wrap the output to the current console width.

Capturing output

There may be situations where you want to capture the output from a Console rather than writing it directly to the terminal. You can do this with the capture() method which returns a context manager. On exit from this context manager, call get() to return the string that would have been written to the terminal. Here’s an example:

from rich.console import Console
console = Console()
with console.capture() as capture:
    console.print("[bold red]Hello[/] World")
str_output = capture.get()

An alternative way of capturing output is to set the Console file to a io.StringIO. This is the recommended method if you are testing console output in unit tests. Here’s an example:

from io import StringIO
from rich.console import Console
console = Console(file=StringIO())
console.print("[bold red]Hello[/] World")
str_output = console.file.getvalue()

Paging

If you have some long output to present to the user you can use a pager to display it. A pager is typically an application on your operating system which will at least support pressing a key to scroll, but will often support scrolling up and down through the text and other features.

You can page output from a Console by calling pager() which returns a context manager. When the pager exits, anything that was printed will be sent to the pager. Here’s an example:

from rich.__main__ import make_test_card
from rich.console import Console

console = Console()
with console.pager():
    console.print(make_test_card())

Since the default pager on most platforms don’t support color, Rich will strip color from the output. If you know that your pager supports color, you can set styles=True when calling the pager() method.

Note

Rich will use the PAGER environment variable to get the pager command. On Linux and macOS you can set this to less -r to enable paging with ANSI styles.

Alternate screen

Warning

This feature is currently experimental. You might want to wait before using it in production.

Terminals support an ‘alternate screen’ mode which is separate from the regular terminal and allows for full-screen applications that leave your stream of input and commands intact. Rich supports this mode via the set_alt_screen() method, although it is recommended that you use screen() which returns a context manager that disables alternate mode on exit.

Here’s an example of an alternate screen:

from time import sleep
from rich.console import Console

console = Console()
with console.screen():
    console.print(locals())
    sleep(5)

The above code will display a pretty printed dictionary on the alternate screen before returning to the command prompt after 5 seconds.

You can also provide a renderable to screen() which will be displayed in the alternate screen when you call update().

Here’s an example:

from time import sleep

from rich.console import Console
from rich.align import Align
from rich.text import Text
from rich.panel import Panel

console = Console()

with console.screen(style="bold white on red") as screen:
    for count in range(5, 0, -1):
        text = Align.center(
            Text.from_markup(f"[blink]Don't Panic![/blink]\n{count}", justify="center"),
            vertical="middle",
        )
        screen.update(Panel(text))
        sleep(1)

Updating the screen with a renderable allows Rich to crop the contents to fit the screen without scrolling.

For a more powerful way of building full screen interfaces with Rich, see Live Display.

Note

If you ever find yourself stuck in alternate mode after exiting Python code, type reset in the terminal

Terminal detection

If Rich detects that it is not writing to a terminal it will strip control codes from the output. If you want to write control codes to a regular file then set force_terminal=True on the constructor.

Letting Rich auto-detect terminals is useful as it will write plain text when you pipe output to a file or other application.

Interactive mode

Rich will remove animations such as progress bars and status indicators when not writing to a terminal as you probably don’t want to write these out to a text file (for example). You can override this behavior by setting the force_interactive argument on the constructor. Set it to True to enable animations or False to disable them.

Note

Some CI systems support ANSI color and style but not anything that moves the cursor or selectively refreshes parts of the terminal. For these you might want to set force_terminal to True and force_interactve to False.

Environment variables

Rich respects some standard environment variables.

Setting the environment variable TERM to "dumb" or "unknown" will disable color/style and some features that require moving the cursor, such as progress bars.

If the environment variable NO_COLOR is set, Rich will disable all color in the output.