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Printing text

Prompt_toolkit ships with a print function that's meant to be (as much as possible) compatible with the built-in print function, but on top of that, also supports colors and formatting.

On Linux systems, this will output VT100 escape sequences, while on Windows it will use Win32 API calls or VT100 sequences, depending on what is available.

Printing plain text

The print function can be imported as follows:

from __future__ import unicode_literals, print_function
from prompt_toolkit import print

print('Hello world')

Warning

If you're using Python 2, make sure to add from __future__ import print_function. Otherwise, it will not be possible to import a function named print.

Formatted text

There are three ways to print colors:

An instance of any of these three kinds of objects is called "formatted text". There are various places in prompt toolkit, where we accept not just plain text (as a strings), but also formatted text.

HTML

:class:`~prompt_toolkit.formatted_text.HTML` can be used to indicate that a string contains HTML-like formatting. It supports the basic tags for bold, italic and underline: <b>, <i> and <u>.

from __future__ import unicode_literals, print_function
from prompt_toolkit import print, HTML

print(HTML('<b>This is bold</b>'))
print(HTML('<i>This is italic</b>'))
print(HTML('<u>This is italic</u>'))

Further, it's possible to use tags for foreground colors:

# Colors from the ANSI palette.
print(HTML('<ansired>This is red</ansired>'))
print(HTML('<ansigreen>This is green</ansigreen>'))

# Named colors (256 color palette, or true color, depending on the output).
print(HTML('<skyblue>This is light pink</skyblue>'))
print(HTML('<seagreen>This is light pink</seagreen>'))
print(HTML('<violet>This is light pink</violet>'))

Both foreground and background colors can also be defined using the fg and bg attributes of any tag:

# Colors from the ANSI palette.
print(HTML('<span fg="#ff0044" bg="seegreen">Red on green</span>'))

Underneath, all tags are mapped to classes from the style sheet. So, if you use a custom tag, then you can assign a style in the stylesheet.

from __future__ import unicode_literals, print_function
from prompt_toolkit import print, HTML
from prompt_toolkit.styles import Style

style = Style.from_dict({
    'aaa': '#ff0066',
    'bbb': '#44ff00 italic',
})

print(HTML('<aaa>Hello</aaa> <bbb>world</bbb>!'), style=style)

ANSI

Some people like to use the VT100 ANSI escape squences to generate output. Natively, this is however only supported on VT100 terminals, but prompt_toolkit can parse these, and map them to a formatted text instances. This means that they will work on Windows as well. The :class:`~prompt_toolkit.formatted.ANSI` class takes care of that.

from __future__ import unicode_literals, print_function
from prompt_toolkit import print, ANSI

print(ANSI('\x1b[31mhello \x1b[32mworld'))

Style/text tuples

Internally, both :class:`~prompt_toolkit.formatted_text.HTML` and :class:`~prompt_toolkit.formatted_text.ANSI` objects are mapped to a list of (style, text) tuples. It is however also possible to create such a list manually. This is a little more verbose, but it's probably the most powerful way of expressing formatted text.

from __future__ import unicode_literals, print_function
from prompt_toolkit import print
from prompt_toolkit.styles import Style

text = [
    ('#ff0066', 'Hello'),
    ('', ' '),
    ('#44ff00 italic', 'World'),
]

print(text, style=style)

Similar to the :class:`~prompt_toolkit.formatted_text.HTML` example, it is also possible to use class names, and separate the styling in a style sheet.

from __future__ import unicode_literals, print_function
from prompt_toolkit import print
from prompt_toolkit.styles import Style

# The text.
text = [
    ('class:aaa', 'Hello'),
    ('', ' '),
    ('class:bbb', 'World'),
]

# The style sheet.
style = Style.from_dict({
    'aaa': '#ff0066',
    'bbb': '#44ff00 italic',
})

print(text, style=style)