A package resource and symbol loading helper library.
Loads resources and symbols from a python package, whether installed as a directory, an egg, or in source form. Also provides some other package-related helper methods, including asset.version(), asset.caller(), and asset.chunks().
$ pip install asset
Load symbols (e.g. functions, classes, or variables) from a package by name:
import asset # load the 'mypackage.foo.myfunc' function and call it with some parameter retval = asset.symbol('mypackage.foo.myfunc')(param='value')
Load data files from a package:
# load the file 'mypackage/templates/data.txt' into string data = asset.load('mypackage:templates/data.txt').read() # or as a file-like stream stream = asset.load('mypackage:templates/data.txt').stream() data = stream.read()
Multiple files can be operated on at once by using globre style wildcards:
# concatenate all 'css' files into one string: css = asset.load('mypackage:static/style/**.css').read() # load all '.txt' files, XML-escaping the data and wrapping # each file in an <node name="...">...</node> element. import xml.etree.ElementTree as ET data = ET.Element('nodes') for item in asset.load('asset:**.txt'): cur = ET.SubElement(data, 'node', name=item.name) cur.text = item.read() data = ET.tostring(data)
Query the installed version of a package:
asset.version('asset') # ==> '0.0.5' asset.version('python') # ==> '2.7' asset.version('no-such-package') # ==> None
Find out what package is calling the current function:
# assuming the call stack is: # in package "zig" a function "x", which calls # in package "bar" a function "y", which calls # in package "foo" a function "callfoo" defined as: def callfoo(): asset.caller() # ==> 'bar' asset.caller(ignore='bar') # ==> 'zig' asset.caller(ignore=['bar', 'zig']) # ==> None
Call all the plugins for a given group:
for plugin in asset.plugins('mypackage.plugins'): plugin.handle()
Filter an object through all the plugins for a given group (if there
are no plugins, this will simply return
result = asset.plugins('mypackage.plugins').filter(thing)
Load all registered plugins, select the ones named
foo and invoke
them (this will fail if there is no
result = asset.plugins('mypackage.plugins').select('foo').handle(thing)
Chunk a file (or any file-like object) into 1 KiB chunks:
with open('/var/binary/data', 'rb') as fp: for chunk in asset.chunks(fp, 1024): # ... do something with `chunk` ...
Chunk an Asset stream (here using the
.chunks alias method):
for chunk in asset.load('mypackage:data/**.bin').chunks(): # ... using the default chunk size (usually 8 KiB) ...
In order to run the unit tests correctly, the
pxml package needs to
be installed as a zipped package (i.e. an “egg”) and the
package needs to be installed unzipped. To accomplish that, do:
$ easy_install --zip-ok pxml $ easy_install --always-unzip globre
The reason is that the unit tests confirm that
asset can load assets
from both zipped and unzipped packages, and can also identify in which
mode it is operating.
TODO: add detailed docs…
If the asset represents a file on the filesystem, is the absolute path to the specified file. Otherwise is None.
Returns the next line from the aggregate asset group stream, as if the assets had been concatenate into a single asset.
IMPORTANT: if an asset ends with content that is not terminated by an EOL token, it is returned as-is, i.e. it does NOT append the first line from the next asset.
Note: because asset.load() does lazy-loading, it only throws a
NoSuchAsset exception when you actually attempt to use the
AssetGroup! If you need an immediate error, use the
Note that it returns itself, so you can do something like:
import asset def my_function_that_returns_an_iterable(): return asset.load(my_spec).peek() # this returns exactly the same thing as the following: # # return asset.load(my_spec) # # but throws an exception early if there are no matching assets.