Using PyPi Libraries
Let's make use of a PyPi library in our project. In this example, we'll use BeautifulSoup to parse an HTML document and actually generate a PuePy component that would render the same content.
Small embedded example
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Using Full CPython/Pyodide
To make use of a library like BeautifulSoup, we will configure PuePy to use the full CPython/Pyoide runtime, rather than the more minimal MicroPython runtime. This is done by specifying the runtime in the <script> tag in index.html:
Requiring packages from pypi
In pyscript-bs.json, we also must specify that we need BeautifulSoup4. This is done by adding it to the packages section of the config file:
pyscript-bs.json
{
"name": "PuePy Tutorial",
"debug": true,
"packages": [
"./puepy-0.4.6-py3-none-any.whl",
"beautifulsoup4"
],
"js_modules": {
"main": {
"https://cdn.jsdelivr.net/npm/morphdom@2.7.2/+esm": "morphdom"
}
}
}
The type attribute in the PyScript <script> tag can have two values:
mpy: Use the MicroPython runtimepy: Use the CPython/Pyodide runtime
See Also
See also the runtimes developer guide for more information on runtimes.
Once the dependencies are specified in the config file, we can import the library in our source file:
Full Example Source
libraries.py
import re
from bs4 import BeautifulSoup, Comment
from puepy import Application, Page, t
app = Application()
PYTHON_KEYWORDS = [
"false",
"none",
"true",
"and",
"as",
"assert",
"async",
"await",
"break",
"class",
"continue",
"def",
"del",
"elif",
"else",
"except",
"finally",
"for",
"from",
"global",
"if",
"import",
"in",
"is",
"lambda",
"nonlocal",
"not",
"or",
"pass",
"raise",
"return",
"try",
"while",
"with",
"yield",
]
class TagGenerator:
def __init__(self, indentation=4):
self.indent_level = 0
self.indentation = indentation
def indent(self):
return " " * self.indentation * self.indent_level
def sanitize(self, key):
key = re.sub(r"\W", "_", key)
if not key[0].isalpha():
key = f"_{key}"
if key == "class":
key = "classes"
elif key.lower() in PYTHON_KEYWORDS:
key = f"{key}_"
return key
def generate_tag(self, tag):
attr_list = [
f"{self.sanitize(key)}={repr(' '.join(value) if isinstance(value, list) else value)}"
for key, value in tag.attrs.items()
]
underscores_tag_name = tag.name.replace("-", "_")
sanitized_tag_name = self.sanitize(underscores_tag_name)
if sanitized_tag_name != underscores_tag_name:
# For the rare case where it really just has to be the original tag
attr_list.append(f"tag={repr(tag.name)}")
attributes = ", ".join(attr_list)
return (
f"{self.indent()}with t.{sanitized_tag_name}({attributes}):"
if tag.contents
else f"{self.indent()}t.{sanitized_tag_name}({attributes})"
)
def iterate_node(self, node):
output = []
for child in node.children:
if child.name: # Element
output.append(self.generate_tag(child))
self.indent_level += 1
if child.contents:
output.extend(self.iterate_node(child))
self.indent_level -= 1
elif isinstance(child, Comment):
for line in child.strip().split("\n"):
output.append(f"{self.indent()}# {line}")
elif isinstance(child, str) and child.strip(): # Text node
output.append(f"{self.indent()}t({repr(child.strip())})")
return output
def generate_app_root(self, node, generate_full_file=True):
header = (
[
"from puepy import Application, Page, t",
"",
"app = Application()",
"",
"@app.page()",
"class DefaultPage(Page):",
" def populate(self):",
]
if generate_full_file
else []
)
self.indent_level = 2 if generate_full_file else 0
body = self.iterate_node(node)
return "\n".join(header + body)
def convert_html_to_context_manager(html, indent=4, generate_full_file=True):
soup = BeautifulSoup(html, "html.parser")
generator = TagGenerator(indentation=indent)
return generator.generate_app_root(soup, generate_full_file=generate_full_file)
@app.page()
class DefaultPage(Page):
def initial(self):
return {"input": "", "output": "", "error": "", "generate_full_file": True}
def populate(self):
with t.div(classes="section"):
t.h1("Convert HTML to PuePy syntax with BeautifulSoup", classes="title is-1")
with t.div(classes="columns is-variable is-8 is-multiline"):
with t.div(classes="column is-half-desktop is-full-mobile"):
with t.div(classes="field"):
t.div("Enter HTML Here", classes="label")
t.textarea(bind="input", classes="textarea")
with t.div(classes="column is-half-desktop is-full-mobile"):
with t.div(classes="field"):
t.div("Output", classes="label")
t.textarea(bind="output", classes="textarea", readonly=True)
with t.div(classes="field is-grouped"):
with t.p(classes="control"):
t.button("Convert", classes="button is-primary", on_click=self.on_convert_click)
with t.p(classes="control"):
with t.label(classes="checkbox"):
t.input(bind="generate_full_file", type="checkbox")
t(" Generate full file")
if self.state["error"]:
with t.div(classes="notification is-danger"):
t(self.state["error"])
def on_convert_click(self, event):
self.state["error"] = ""
try:
self.state["output"] = convert_html_to_context_manager(
self.state["input"], generate_full_file=self.state["generate_full_file"]
)
except Exception as e:
self.state["error"] = str(e)
app.mount("#app")
PyScript documentation on packages
For more information, including packages available to MicroPython, refer to the PyScript docs.