Best way to display only URL domain using jinja2 - python

I have URLs stored in a Django model that I would like to display on a template, but I would only like to display the domain like this:
original_url:
https://wikipedia.org/wiki/List_of_chemical_process_simulators
display:
wikipedia.org/...
Would it be better to handle this on entirely on the back-end, font-end, or a custom function on with jinja2?

If it is something you would later reuse in the templates throughout the project and, taking into account that there is a pretty simple logic involved, defining a custom template filter would be perfectly okay here.
Use urlparse.urlparse() to get the domain name:
>>> from urlparse import urlparse
>>> from jinja2 import Environment, Template
>>>
>>> def get_domain(url):
... return "%s/..." % urlparse(url).netloc
...
>>>
>>> env = Environment()
>>> env.filters['domain'] = get_domain
>>>
>>> template = env.from_string('{{ url|domain }}')
>>> template.render(url='https://wikipedia.org/wiki/List_of_chemical_process_simulators')
u'wikipedia.org/...'
This is a simple example, you should additionally provide an error-handling mechanism in case urlparse() would fail parsing the url passed in.

The best way would probably be a custom template filter as answered by #alecxe, but in case you can't, here is a non-fool-proof way for future reference.
{{ original_url.rpartition("//")[-1] }}
https://wikipedia.org/wiki/List_of_chemical_process_simulators → wikipedia.org/wiki/List_of_chemical_process_simulators
//example.net/path/to/file → example.net/path/to/file
ftp://example.net/pub → example.net/pub
Get just the domain name (hostname):
{{ original_url.rpartition("//")[-1].partition("/")[0] }}
https://wikipedia.org/wiki/List_of_chemical_process_simulators → wikipedia.org
//example.net/path/to/file → example.net
ftp://example.net/pub → example.net

Related

Sphinx - Let the customize HTML know the variable

# conf.py
language='en'
html_extra_path = ["customize.html"]
<!-- customize.html -->
{{ variables }} <!-- from the conf.py -->
{{ language }} <!-- expected output: en -->
How can I let the customize.html know the variables is from the config?
.. note:: assume the customize.html file is not in the documents of the theme.
I can do it by myself with Jinja, but this is not what I want.
I think sphinx already provides a way to do the things, does anyone know what is it?
Solution 1: modify sphinx-build.exe process
I hack the code (i.e. you could not build with sphinx-build.exe directly) to achieve it.
First, we observe sphinx-build.exe do what things.
# site-packages\Sphinx-x.x.x.dist-info\entry_points.txt
[console_scripts]
...
sphinx-build = sphinx.cmd.build:main
...
and then you know it actually calls sphinx.cmd.build:main to run,
you can reference it and make modifications to satisfying you.
For example:
import sphinx.cmd.build
from sphinx.application import Sphinx
from sphinx.builders.html import StandaloneHTMLBuilder
from sphinx.cmd.build import patch_docutils, docutils_namespace, handle_exception, Sphinx
def setup_extra_html(app):
html_builder = app.builder
ctx = {attr: app.config[attr] for attr in dir(app.config) if not attr.startswith('_')}
html_builder.globalcontext = ctx.copy()
# Please put your HTML to the ``templates_path`` that you define, since it concept about the BuiltinTemplateLoader.pathchain
pagename = 'disqus_statistic' # <-- your HTML, you can set it on the conf.py and then get it with ``ctx``
templatename = f'{pagename}.html'
html_builder.handle_page(pagename=pagename, addctx=dict(), templatename=templatename, outfilename=None)
def your_build_main(*args):
...
try:
with patch_docutils(source_dir)), docutils_namespace():
app = Sphinx(...)
if isinstance(app.builder, StandaloneHTMLBuilder):
setup_extra_html(app)
app.build(force_all=False, filenames)
return app.statuscode
except (Exception, KeyboardInterrupt) as exc:
...
cmd_list = [source_dir, output_dir, '-b', 'html', ...]
sphinx.cmd.build.build_main = your_build_main # override it.
sphinx.cmd.build.main(cmd_list) # it will call sphinx.cmd.build.build_main
And now, the following contents will work as you expected.
<!-- original disqus_statistic.html -->
{%- if html_favicon %}
Test Icon
{%- endif %}
{{ language }}
you should complete the detail by yourself since the code is too long.
or you can refer my script of sphinx_cmd_build.py
Solution 2: add the plugin (extension)
tl;dr
# your_extension.py
from sphinx.application import Sphinx
from sphinx.builders.html import StandaloneHTMLBuilder
import pathlib
def expand_init_builder(app):
Sphinx._init_builder(app)
do_something(app)
def setup(app: Sphinx):
app.add_config_value('config_value_define_by_you', default='', rebuild=True)
app._init_builder = lambda: expand_init_builder(app)
def do_something(app: Sphinx):
user_config = {attr: app.config[attr] for attr in dir(app.config) if not attr.startswith('_')} # all variable of conf.py
# user_config.update(...) # Hard coding is fine, but not recommend.
user_config.update(dict(Path=pathlib.Path)) # recommend you, it's useful.
html_builder: StandaloneHTMLBuilder = app.builder
html_builder.globalcontext = user_config
html_builder.handle_page(pagename=page_name, addctx=dict(), templatename=template_name, outfilename=None)
# conf.py
# sys.path.insert(...)
extensions.append('your_extension') # Make sure your scrips can found in sys.path.
# https://www.sphinx-doc.org/en/master/usage/configuration.html#confval-templates_path
templates_path = ['_templates/sphinx_rtd_theme'] # I hope you know what I mean... see the above link.
# I put my_html.html in ``_templates/sphinx_rtd_theme/my_html.html``
config_value_define_by_you = "https://github.com/CarsonSlovoka/typing-game"
<!-- my_html.html -->
{{ Path(config_value_define_by_you).name }} <!-- render result: typing-game -->
Long story (explain solutions2)
Sphinx-build.exe doing what things?
init # <-- and this one is not we cared.
create an instance of Sphinx(), the instance is app. i.e. app = Sphinx(...)
app.build
it calls the builder to start building, the builder format which defines by the user, in my case the build format is HTML, so its builder is StandaloneHTMLBuilder
And then, you know all files that are created by the builder.
The idea is: if we can get the builder, then we can do anything we want.
You will find the builder that is creat after the Sphinx(...),
so the solutions one, I tell you setup_extra_html after the app = Sphinx(...)
If you don't like to write these codes and think it's too complex.
The second way is to write the extensions,
the concept is the same as the above -- try to get the builder
you see the Sphinx(...) its constructor, and you find the code as below
class Sphinx:
def __init__(...):
...
# load all user-given extension modules
for extension in self.config.extensions:
self.setup_extension(extension) # <-- the extension you write
...
# create the builder
self.builder = self.create_builder(buildername) <-- this is we want
self._init_env(freshenv)
self._init_builder()
And then, you know the normal way to create the extensions which couldn't get the builder,
but you notice that if you do something after the self._init_builder() finished, then it's ok.
I provide my projects for your reference.
The real things that I want is, I want to create a page and I hope it can count the numbers of comments for each article, and show me.
You will understand, if I don't use the sphinx, but choose naming convention, then I must hard code a lot of things.
solution 1: https://github.com/CarsonSlovoka/typing-game/commit/376c9e20eac4a3c9b269b5bfbc8adb85ad9f6d36
solution 2: https://github.com/CarsonSlovoka/typing-game/commit/69411e15f1ace853edcafafc14759ba79b7ac288
demo: https://carsonslovoka.github.io/typing-game/en/doc.html#statistic -> and then, click counts of the Disqus.
original HTML
I hope you will get help and think it useful!

Pyramid: How to get all app's routes within a view?

I want to see all the routes which my application has. Return them as a response like key=>value pair:
'route1' => '{foo:\w+}'
'route2' => '{baz:\w+\d+}'
... and so on
But I don't know how to get them within my view. For example, this is my view. I want it to return a map of routes. I do this:
#view_config(route_name='route1')
def someView(request):
routes = request.registry.settings.getRoutes() ## what should I print here to get a map of routes?
r = ''
for k,v in sorted(routes.items()):
r += str(k) + "=>" + str(v) + "<br/>";
return Response(r)
There is a RoutesConfiguratorMixin class with get_routes_mapper method. I tried to import the class and called its method but got an error that no registry was in the instance of it:
from pyramid.config.routes import RoutesConfiguratorMixin as Router
r = Router();
routes = r.get_routes_mapper();
## ... and the same code as above
Doesn't work.
There are 2 ways, one is supported (public) and one is unsupported (private).
Option #1 is to use the introspector and is explained here.
Option #2 is to use the route mapper (which is not a public api), in the way that the pyramid debugtoolbar does in its routes panel.
Pyramid installs a bin script called proutes for that purpose.
Install pshell then
pshell to login to pshell with your app config.
then run
print("\n".join([r.path for r in app.routes_mapper.routelist]))

Is inline code allowed in Jinja templates?

I'm using Jinja on my site and I like it.
I've come across a simple need. How to display today's date? Is there a way to inline some Python code in a Jinja template?
import datetime
now = datetime.datetime.utcnow()
print now.strftime("%Y-%m-%d %H:%M")
This article says no, but suggests using a macro or a filter?
Really? Must we resort to all that? OK, what would that look like in this case?
No, there is no way to inline Python into Jinja. However, you can add to the constructs that Jinja knows by extending the Environment of the template engine or the global namespace available to all templates. Alternately, you can add a filter that let's you format datetime objects.
Flask stores the Jinja2 Environment on app.jinja_env. You can inject new context into the environment by either adding to this dictionary directly, or by using the #app.context_processor decorator.
Whatever path you choose, this should be done while you are setting up the application, before you have served any requests. (See the snippets section of the website for some good examples of how to set up filters - the docs contain a good example of adding to the global variables).
The current answers are correct for pretty much every situation. However there are some very rare cases where you would want to have python code inside the template. In my case I want to use it to preprocess some latex files and I would prefer to keep the python code generating table values, plots, etc, inside the latex file it self.
So I made a Jinja2 extension that adds a new "py" block allowing python code to be written inside the template. Please keep in mind that I had to do some questionable work-arounds to get this to work, so I'm not 100% sure in which situations it fails or behaves unexpectedly.
This is an example template.
Foo was given to the template
foo: {{ foo }}
Bar was not, so it is missing
bar is missing: {{ bar == missing }}
{% py %}
# Normal python code in here
# Excess indentation will be removed.
# All template variables are accessible and can be modified.
import numpy as np
a = np.array([1, 2])
m = np.array([[3, 4], [5, 6]])
bar = m # a * foo
# It's also possible to template the python code.
{% if change_foo %}
foo = 'new foo value'
{% endif %}
print("Stdio is redirected to the output.")
{% endpy %}
Foo will have the new value if you set change_foo to True
foo: {{ foo }}
Bar will now have a value.
bar: {{ bar }}
{% py %}
# The locals from previous blocks are accessible.
m = m**2
{% endpy %}
m:
{{ m }}
The output if we set the template parameters to foo=10, change_foo=True is:
Foo was given to the template
foo: 10
Bar was not, so it is missing
bar is missing: True
Stdio is redirected to the output.
Foo will have the new value if you set change_foo to True
foo: new foo value
Bar will now have a value.
bar: [110 170]
m:
[[ 9 16]
[25 36]]
The extension with a main function to run the example.
from jinja2 import Environment, PackageLoader, nodes
from jinja2.ext import Extension
from textwrap import dedent
from io import StringIO
import sys
import re
import ctypes
def main():
env = Environment(
loader=PackageLoader('python_spike', 'templates'),
extensions=[PythonExtension]
)
template = env.get_template('emb_py2.txt')
print(template.render(foo=10, change_foo=True))
var_name_regex = re.compile(r"l_(\d+)_(.+)")
class PythonExtension(Extension):
# a set of names that trigger the extension.
tags = {'py'}
def __init__(self, environment: Environment):
super().__init__(environment)
def parse(self, parser):
lineno = next(parser.stream).lineno
body = parser.parse_statements(['name:endpy'], drop_needle=True)
return nodes.CallBlock(self.call_method('_exec_python',
[nodes.ContextReference(), nodes.Const(lineno), nodes.Const(parser.filename)]),
[], [], body).set_lineno(lineno)
def _exec_python(self, ctx, lineno, filename, caller):
# Remove access indentation
code = dedent(caller())
# Compile the code.
compiled_code = compile("\n"*(lineno-1) + code, filename, "exec")
# Create string io to capture stdio and replace it.
sout = StringIO()
stdout = sys.stdout
sys.stdout = sout
try:
# Execute the code with the context parents as global and context vars and locals.
exec(compiled_code, ctx.parent, ctx.vars)
except Exception:
raise
finally:
# Restore stdout whether the code crashed or not.
sys.stdout = stdout
# Get a set of all names in the code.
code_names = set(compiled_code.co_names)
# The the frame in the jinja generated python code.
caller_frame = sys._getframe(2)
# Loop through all the locals.
for local_var_name in caller_frame.f_locals:
# Look for variables matching the template variable regex.
match = re.match(var_name_regex, local_var_name)
if match:
# Get the variable name.
var_name = match.group(2)
# If the variable's name appears in the code and is in the locals.
if (var_name in code_names) and (var_name in ctx.vars):
# Copy the value to the frame's locals.
caller_frame.f_locals[local_var_name] = ctx.vars[var_name]
# Do some ctypes vodo to make sure the frame locals are actually updated.
ctx.exported_vars.add(var_name)
ctypes.pythonapi.PyFrame_LocalsToFast(
ctypes.py_object(caller_frame),
ctypes.c_int(1))
# Return the captured text.
return sout.getvalue()
if __name__ == "__main__":
main()
You can add to global variables which can be accessed from Jinja templates. You can put your own function definitions in there, which do whatever you need.

How do I format a date in Jinja2?

Using Jinja2, how do I format a date field? I know in Python I can simply do this:
print(car.date_of_manufacture.strftime('%Y-%m-%d'))
But how do I format the date in Jinja2?
There are two ways to do it. The direct approach would be to simply call (and print) the strftime() method in your template, for example
{{ car.date_of_manufacture.strftime('%Y-%m-%d') }}
Another, sightly better approach would be to define your own filter, e.g.:
from flask import Flask
import babel
app = Flask(__name__)
#app.template_filter()
def format_datetime(value, format='medium'):
if format == 'full':
format="EEEE, d. MMMM y 'at' HH:mm"
elif format == 'medium':
format="EE dd.MM.y HH:mm"
return babel.dates.format_datetime(value, format)
(This filter is based on babel for reasons regarding i18n, but you can use strftime too). The advantage of the filter is, that you can write
{{ car.date_of_manufacture|format_datetime }}
{{ car.date_of_manufacture|format_datetime('full') }}
which looks nicer and is more maintainable. Another common filter is also the "timedelta" filter, which evaluates to something like "written 8 minutes ago". You can use babel.dates.format_timedelta for that, and register it as filter similar to the datetime example given here.
Here's the filter that I ended up using for strftime in Jinja2 and Flask
#app.template_filter('strftime')
def _jinja2_filter_datetime(date, fmt=None):
date = dateutil.parser.parse(date)
native = date.replace(tzinfo=None)
format='%b %d, %Y'
return native.strftime(format)
And then you use the filter like so:
{{car.date_of_manufacture|strftime}}
I think you have to write your own filter for that. It's actually the example for custom filters in the documentation.
If you are dealing with a lower level time object (I often just use integers), and don't want to write a custom filter for whatever reason, an approach I use is to pass the strftime function into the template as a variable, where it can be called where you need it.
For example:
import time
context={
'now':int(time.time()),
'strftime':time.strftime } # Note there are no brackets () after strftime
# This means we are passing in a function,
# not the result of a function.
self.response.write(jinja2.render_template('sometemplate.html', **context))
Which can then be used within sometemplate.html:
<html>
<body>
<p>The time is {{ strftime('%H:%M%:%S',now) }}, and 5 seconds ago it was {{ strftime('%H:%M%:%S',now-5) }}.
</body>
</html>
You can use it like this in template without any filters
{{ car.date_of_manufacture.strftime('%Y-%m-%d') }}
Google App Engine users : If you're moving from Django to Jinja2, and looking to replace the date filter, note that the % formatting codes are different.
The strftime % codes are here: http://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior
You can use it like this in jinja template
{{ row.session_start_date_time.strftime('%d-%m-%Y %H:%M:%S')}}
In this code the field name is row.session_start_date_time.
in flask, with babel, I like to do this :
#app.template_filter('dt')
def _jinja2_filter_datetime(date, fmt=None):
if fmt:
return date.strftime(fmt)
else:
return date.strftime(gettext('%%m/%%d/%%Y'))
used in the template with {{mydatetimeobject|dt}}
so no with babel you can specify your various format in messages.po like this for instance :
#: app/views.py:36
#, python-format
msgid "%%m/%%d/%%Y"
msgstr "%%d/%%m/%%Y"
I use this filter, it's in Spanish but you may change the names as you need.
#app.template_filter('datetime')
def date_format(value):
months = ('Enero','Febrero',"Marzo","Abril","Mayo","Junio","Julio","Agosto","Septiembre","Octubre","Noviembre","Diciembre")
month = months[value.month-1]
hora = str(value.hour).zfill(2)
minutos = str(value.minute).zfill(2)
return "{} de {} del {} a las {}:{}hs".format(value.day, month, value.year, hora, minutos)
There is a jinja2 extension you can use just need pip install (https://github.com/hackebrot/jinja2-time)

How Do I Use A Decimal Number In A Django URL Pattern?

I'd like to use a number with a decimal point in a Django URL pattern but I'm not sure whether it's actually possible (I'm not a regex expert).
Here's what I want to use for URLs:
/item/value/0.01
/item/value/0.05
Those URLs would show items valued at $0.01 or $0.05. Sure, I could take the easy way out and pass the value in cents so it would be /item/value/1, but I'd like to receive the argument in my view as a decimal data type rather than as an integer (and I may have to deal with fractions of a cent at some point). Is it possible to write a regex in a Django URL pattern that will handle this?
It can be something like
urlpatterns = patterns('',
(r'^item/value/(?P<value>\d+\.\d{2})/$', 'myapp.views.byvalue'),
... more urls
)
url should not start with slash.
in views you can have function:
def byvalue(request,value='0.99'):
try:
value = float(value)
except:
...
I don't know about Django specifically, but this should match the URL:
r"^/item/value/(\d+\.\d+)$"
If the values to be accepted are only $0.01 or $0.05, the harto's pattern may be specified like this:
r"^/item/value/(\d\.\d{2})$"
Don't use »
url(r"^item/value/(?P<dollar>\d+\.\d{1,2})$", views.show_item, name="show-item"),
It will only match the URL patterns like /item/value/0.01, /item/value/12.2 etc.
It won't match URL patterns like /item/value/1.223, /item/value/1.2679 etc.
Better is to use »
url(r"^item/value/(?P<dollar>\d+\.\d+)$", views.show_item, name="show-item"),
It will match URL patterns like /item/value/0.01, /item/value/1.22, /item/value/10.223, /item/value/1.3 etc.
Finally you can design your views.py something like
This is just for an example.
# Make sure you have defined Item model (this is just an example)
# You use your own model name
from .models import Item
def show_item(request, dollar):
try:
# Convert dollar(string) to dollar(float).
# Which gets passed to show_item() if someone requests
# URL patterns like /item/value/0.01, /item/value/1.22 etc.
dollar = float(dollar);
# Fetch item from Database using its dollar value
# You may use your own strategy (it's mine)
item = Item.objects.get(dollar=dollar);
# Make sure you have show_item.html.
# Pass item to show_item.html (Django pawered page) so that it could be
# easily rendered using DTL (Django template language).
return render(request, "show_item.html", {"item": item});
except:
# Make sure you have error.html page (In case if there's an error)
return render(request, "error.html", {});

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