Let's do a walk through a memory filesystem. 

.. >>> import py


working with directories
---------------------------------

Let's create some directories and list them from memory::

>>> fs = py.fs.MemoryFS()
>>> fs.mkdir("x")
>>> fs.mkdir("y")
>>> fs.listdir()
['x', 'y']


Creating, removing and reading files
---------------------------------------------

>>> f = fs.open('x/file', 'w')
>>> f.write("hello world")
>>> f.close()
>>> fs.listdir("x")
['file']
>>> f = fs.open("x/file", 'r')
>>> f.readlines()
['hello world']
>>> f.seek(6)
>>> f.read(3)
"wor"
>>> f.read()
"ld"
>>> f.close()
>>> fs.remove("y")
>>> fs.listdir()
['x']
>>> fs.remove("non-existent")
py.error.ENOENT 

stat / checking for meta information 
---------------------------------------

>>> stat = memory.stat("x")
>>> stat.isdir()
True
>>> stat.isfile()
False
>>> stat.exists()
True
>>> stat.islink()
False

Linking to other objects 
--------------------------------------------------------

First an example how to link internally, i.e. within the 
filesystem. 

>>> fs.link("newitem", "x")
>>> fs.stat("newitem").islink()
True
>>> fs.stat("newitem").isfile()
True
>>> fs.remove("newitem")  # only deletes the link itself
>>> fs.stat("x").exists()

cross-filesystem references 
---------------------------------

>>> otherfs = py.fs.MemoryFS()

XXX 

>>> fs.setproxy("newitem", otherfs, "otheritem")
>>> fs.stat("newitem").exists()
False
>>> otherfs.mkdir("otheritem")