pyfs

Mount python — it's fun, not a typo, and next to pointless!

pyfs is a FUSE implementation that gives a filesystem view on Python modules.

Why is that cool? You can do stuff like this:

lib$ os/path/join /this is a path
/this/is/a/path

Yes, that's os.path.join doing the work. Or look at this:

lib$ string/capwords "let's do some python … not."
Let's Do Some Python … Not.
lib$ string/capwords once-more-unto-the-breach -
Once-More-Unto-The-Breach

You can have a look at the docstring, if need be:

lib$ os/path/join -h
usage: join [-h] [funcargs [funcargs ...]]

Join two or more pathname components, inserting '/' as needed. If any
component is an absolute path, all previous path components will be discarded.
An empty last part will result in a path that ends with a separator.

positional arguments:
  funcargs

optional arguments:
  -h, --help  show this help message and exit
~/test-pyfs$ 

Come on, that is cool, yes? Sure, it's a whee bit superfluous, a solution to no problem, but, hey, it'll get much better soon! Promise!

The whole thing started, when I had a look at Python's FUSE modules. If you want an overview about those, go over there.

The structure of the filesystem

How does the root of the mountpoint look like? For example, like so:

$ tree -L 2
.
├── bin
├── dot
├── lib
│   ├── __builtin__
│   ├── json
│   ├── os
│   ├── re
│   ├── string
│   └── sys
└── run
    └── modules

(Slightly cut.)

Runtime modifications

Wonder what run/modules does? It's a file. You can cat it:

$ cat run/modules 
sys
json
os
string
__builtin__

But, you can also add modules:

$ echo re >> run/modules 
$ ls lib
__builtin__  json  os  re  string  sys

And then you can use it:

$ lib/re/match "\d+a" 33434a
<_sre.SRE_Match object at 0x10641d0>

Or, you can get rid of the imported modules:

$ echo > run/modules 
$ ls lib/
$ cat run/modules 
$ 

Piping

Use pipes to concatenate Python commands. The dash character, “-”, marks the place where each element should go.

lib$ echo Hello World | string/index - Wor | string/zfill - 10
0000000006

bin

Add bin/ to your PATH and get everything from builtin readily available:

$ pow 2 10
1024

Object attributes

You can access attributes of an object using the directory dot. The attribute names cannot be resolved automatically, but if you know what you want, you'll get it.

echo Hallo | dot/__doc__
str(object='') -> string

Return a nice string representation of the object.
If the argument is a string, the return value is the same object.

If the attribute is callable, it will be called with the given arguments.

$ echo Hello world | dot/split | lib/string/join ' -> '
Hello -> world

$ echo Hello=world | dot/split = | lib/string/join ' -> '
Hello -> world

How to use it

Get fusepy.

pip install fusepy

Clone the repo and run:

mkdir mountpoint
python  -m pyfs.filesystem mountpoint

(No pip package / setup.py just yet, sorry!)

In the dir mountpoint you'll find the filesystem to play with.

Unmount using:

fusermount -u mountpoint

More weird ideas for the future

• Transform arguments by introspection:
  • positional parameters are made explicit by adding them to the argparse Parser
  • keyword parameters are turned into optional argparse arguments
• $ lib/SimpleHttpServer/.self 8080 # python -m SimpleHttpServer 8080
• provide a meta function to install packages in some virtualenv, so they can be loaded. (can I create a virtualenv at startup in memory and use that? /temp would be another option)

To be continued …