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.

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().

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 text 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.

File output

The Console object will write to standard output (i.e. the terminal). You can also tell the Console object to write to another file by setting the file argument on the constructor – which should be a file-like object opened for writing text. One use of this capability is to create a Console for writing to standard error by setting file to sys.stderr. Here’s an example:

import sys
from rich.console import Console
error_console = Console(file=sys.stderr)
error_console.print("[bold red]This is an error!")

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()

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.

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.