A purely-functional HTML builder for Python. Think JSX rather than templates.
htbuilder lets you build HTML strings using a purely functional syntax in Python. Why use templating languages when you can just use functions?
(PS: If you like this, check out jsbuild which lets you build JavaScript strings by simply annotating Python functions!)
Just PIP it!
pip install htbuilder
Just import tags like div
with from htbuilder import div
, then call them:
# Import any tag you want from htbuilder, and it just works!
# (This syntax requires Python 3.7+. See below for an alternate syntax)
from htbuilder import div
dom = div('Hello world!')
Then you can get the string output by calling str()
on it:
str(dom)
# Returns '<div>Hello world!</div>'
...which means you can also just print()
to see it in the terminal:
print(dom)
# Prints '<div>Hello world!</div>'
To specify attributes, call the tag builder with keyword args:
print(
div(id='sidebar', foo='bar')
)
# Prints '<div id="sidebar" foo="bar"></div>'
To specify both attributes and children, first specify the attributes using keyword args, then pass the children afterwards inside a new set of parentheses:
print(
div(id='sidebar', foo='bar')(
"Hello world!"
)
)
# Prints '<div id="sidebar" foo="bar">Hello world!</div>'
This is required because Python doesn't allow you to pass keyword arguments before you pass normal arguments.
Want to output multiple children? Just pass them all as arguments:
from htbuilder import div, ul, li, img
dom = (
div(id='container')(
ul(_class='greetings')(
li('hello'),
li('hi'),
li('whattup'),
)
)
)
print(dom)
# Prints this (but without added spacing):
# <div id="container">
# <ul class="greetings">
# <li>hello</li>
# <li>hi</li>
# <li>whattup</li>
# </ul>
# </div>
You can also pass any iterable to specify multiple children, which means you can simply use things like generator expressions for great awesome:
from htbuilder import div, ul, li, img
image_paths = [
'http://myimages.com/foo1.jpg',
'http://myimages.com/foo2.jpg',
'http://myimages.com/foo3.jpg',
]
dom = (
div(id='container')(
ul(_class='image-list')(
li(img(src=image_path, _class='large-image'))
for image_path in image_paths
)
)
)
print(dom)
# Prints:
# <div id="container">
# <ul class="image-list">
# <li><img src="http://myimages.com/foo1.jpg" class="large-image"/></li>
# <li><img src="http://myimages.com/foo2.jpg" class="large-image"/></li>
# <li><img src="http://myimages.com/foo3.jpg" class="large-image"/></li>
# </ul>
# </div>
And because it's just Python, you can use an if/else expression to conditionally insert elements:
use_bold = True
dom = (
div(
b("bold text")
if use_bold else
"normal text"
)
)
print(dom)
# Prints: <div><b>bold text</b></div>
We provide helpers to write styles without having to pass huge style strings as
arguments. Instead, just use handy builders like styles()
, classes()
,
fonts()
, along with helpers you can import from the units
and funcs
modules.
# styles, classes, and fonts are special imports to help build attribute strings.
from htbuilder import div, styles, classes, fonts
# You can import anything from .units and .funcs to make it easier to specify
# units like "%" and "px", as well as functions like "rgba()" and "rgba()".
from htbuilder.units import percent, px
from htbuilder.funcs import rgba, rgb
bottom_margin = 10
is_big = True
dom = (
div(
_class=classes('btn', big=is_big)
style=styles(
color='black',
font_family=fonts('Comic Sans', 'sans-serif'),
margin=px(0, 0, bottom_margin, 0),
padding=(px(10), percent(5))
box_shadow=[
(0, 0, px(10), rgba(0, 0, 0, 0.1)),
(0, 0, '2px', rgb(0, 0, 0)),
],
)
)
)
# Prints:
# <div
# class="btn big"
# style="
# color: black;
# font-family: "Comic Sans", "sans-serif";
# margin: 0 0 10px 0;
# padding: 10px 5%;
# box-shadow: 0 0 10px rgba(0, 0, 0, 0.1), 0 0 2px rgb(0, 0, 0);
# "></div>
Like most popular languages, Python doesn't support dashes in identifiers. So if you want to build
an element that includes dashes in the tag name or attributes, like <my-element foo-bar="baz">
, you can
do so by using underscores instead:
from htbuilder import my_element
dom = my_element(foo_bar="baz")
print(dom)
# Prints:
# <my-element foo-bar="baz"></my-element>
The word class
is reserved in Python, so if you want to set an element's class
attribute you
should prepend it with an underscore like this:
dom = div(_class="myclass")
print(dom)
# Prints:
# <div class="myclass"></div>
This works because underscores preceding or following any identifier are automatically stripped away for you.
If using Python < 3.7, the import should look like this instead:
from htbuilder import H
div = H.div
ul = H.ul
li = H.li
img = H.img
# ...etc