Develop Reference

Python starter program : Moving files

Looking to make some use out of Python! I wanted to write a script to move all those carelessly placed .jpg files from my desktop.
Thing, is the script I'm using doesn't seem to be finding anything.
thoughts?
import os, shutil, glob
dst_fldr = "~/path/Desktop/newfolder";
for jpg_file in glob.glob("~/path/Desktop"+"\\*.jpg"):
print jpg_file + "will be moved to " + dst_fldr
shutil.move(jpg_file, dst_fldr);

~ is not a character that glob understands (it's a character that bash understands and expands). You'll have to provide a full path.
dst_fldr = "/path/to/Desktop/newfolder";
In addition, you'd want to modify the wildcard search, to something like this:
glob.glob("/path/to/Desktop/*.jpg"):
If your python script resides in Desktop, you can drop the /path/to/Desktop part of the path in both cases.
With these changes in place, I believe you're good to go.

Python - Windows maximum directory path length workaround

The problem is the character limit for the path in windows when creating multiple directories using pythons os.makedirs()
I found this post when searching for my problem before posting this:
python win32 filename length workaround
Now the chosen answer suggests the prefix workaround but my question here is, is there a way to ensure functionality in Windows and UNIX?
The other approach I thought of was to create the folders one by one and then create the file so that you never exceed the path length, but I can't figure out the obvious bug in the code.
path = ['folder1/s1/s1/abc.txt',
'folder1/s1/s2/def.txt']
def makedirs(path):
explode = path.split('/')
for i in range(len(explode)-1):
os.mkdir(explode[i])
os.chdir(explode[i])
if i == len(explode) -2:
download_file(explode[i+1])
# something to go back here
os.chdir('../' * (len(explode)-3)) # ??
makedirs(path[0])
Now this works for only the first line because I can't figure out how to get back to the root or reset it. Without the 'reset' the folders are being under each other:
folder1/s1/s1/folder1/s1/s1/abc.txt (or something like that)
I could set the path from root to reset it but then we might run into the same issue of reaching the max length. Any help on how to get this working on both OS would be appreciated!
Please feel free to point out where I'm wrong.

you need to use unc path and unicode filenames, but not all python functions are aware of this, os.mkdir works while os.makedirs not
import os
path = u'\\\\?\\c:\\'
for i in xrange(1000):
path += u'subdir\\'
os.mkdir(path)
but it's better to give also the code to remove them, windows explorer is unable to delete
import os
path = u'\\\\?\\c:\\'
for i in xrange(1000, 0, -1):
try:
os.rmdir(path + (u'subdir\\' * i))
except:
pass

Per this stackoverflow answer: while chdir can go up one directory with os.chdir(".."), the platform-agnostic way is: os.chdir(os.pardir).
Either call this N times in a loop;
or try an unreadable one-liner like this (untested):
os.chdir(os.path.join(*([os.pardir] * NUM_TIMES)))
(Instead of path.split('/'), you could also use the method described here for it to work on all operating systems)

Generating directories/sub-directories and files

Hi I am currently a beginner to the python language, it is also my first language too. I need some help I am finding it difficult to know what to use to generate permanent directories sub directories and files, for eg; I want the path to generate whatever path i enter if the directories etc. don't exist, i want them created, so I enter C:\user\python\directory\sub-directory\file, then i cant workout what i should import to do the following job.
I am using Python 3.2, any advice?

You can do:
import os
os.makedirs('a/b/c', exist_ok=True)
http://docs.python.org/py3k/library/os.html

f = open("c:\file\path","w")
f.write("content of file")
First, you open the file, storing it in variable f.
You then write to it, using f.write()
Python will create the file and path if it does not exist, I think. (I am sure I've done this before, but I can't remember)
When you have finished using the file, you should use
f.close()
to close the file safely.

converting/mapping linux reference path without altering the file?

Currently on a project that my client needs the reference file path to
remain in linux format. For example
A.ma , referencing objects from --> //linux/project/scene/B.ma
B.ma , referencing objects from --> //linux/project/scene/C.ma
Most of our Maya license here however are on Windows. I can run a
Python script that convert all the paths windows paths and save the
file. For example
Z:\project\scene\B.ma
However I'm trying to figure out a way to do this without converting
or altering the original file.... I'll try to explain what I'm trying to do.
Run the script to open the file.
The script checks for the linux formatted reference path, and all
child path down the hierarchy.
Maps all paths to their appropriate windows formatted paths.
Giving the animators the ability to "save" files normally without running a separate save script.
Is this possible to achieve this with Python script? Or will I need a
fully-compiled plug in to get this to work?
Any suggestion is greatly appreciated.
edit: Thank you for your input.
A little more clarification. The projects were set up for us by a remote company and part of the requirement is that we have to keep the path as is. They come as absolute path and we have no choice in that matter.
We match the mount //linux/ on our Fedora workstations. That same drive is mapped to Z:\ on our windows workstations. We only have 2 Maya license for Linux tho which is why I'm trying to do this.

Here is a solution. First step is to create a dict that keeps track of linux/windows references (don't forget to import the re module for regexp):
>>> def windows_path(path):
return path.replace('//linux', 'Z:').replace('/', '\\')
>>> reg = re.compile('(\w+\.ma) , referencing objects from --> (.*)')
>>> d = {}
>>> for line in open('D:\\temp\\Toto.txt'):
match = reg.match(line)
if match:
file_name = match.groups()[0]
linux_path = match.groups()[1]
d[file_name] = (linux_path, windows_path(linux_path))
>>> d
{'B.ma': ('//linux/project/scene/C.ma', 'Z:\\project\\scene\\C.ma'),
'A.ma': ('//linux/project/scene/B.ma', 'Z:\\project\\scene\\B.ma')}
Then you just need to loop on this dict to ask for file save:
>>> for file_name in d.keys():
s = raw_input('do you want to save file %s ? ' % file_name)
if s.lower() in ('y', 'yes'):
# TODO: save your file thanks to d[file][0] for linux path,
# d[file][1] for windows path
print '-> file %s was saved' % file_name
else:
print '-> file %s was not saved' % file_name
do you want to save file B.ma ? n
-> file B.ma was not saved
do you want to save file A.ma ? yes
-> file A.ma was saved

Many Windows applications will interpret paths with two leading "/"s as UNC paths. I don't know if Maya is one of those, but try it out. If Maya can understand paths like "//servername/share/foo", then all you need to do is set up a SMB server named "linux", and the paths will work as they are. I would guess that this is actually what your client does, since the path "//linux" would not make sense in a Linux-only environment.

You can use environment variables to do this. Maya will expand environment vars present in a file path, you could use Maya.env to set them up properly for each platform.

What you are looking for is the dirmap mel command. It is completely non-intrusive to your files as you just define a mapping from your linux paths to windows and/or vice versa. Maya will internally apply the mapping to resolve the paths, without changing them when saving the file.
To setup dirmap, you need to run a MEL script which issues the respective commands on maya startup. UserSetup.mel could be one place to put it.
For more details, see the official documentation - this particular link points to maya 2012, the command is available in Maya 7.0 and earlier as well though:
http://download.autodesk.com/global/docs/maya2012/en_us/Commands/dirmap.html

Accessing a file relatively in Python if you do not know your starting point?

Hey. I've got a project in Python, whose directory layout is the following:
root
|-bin
|-conf
|-[project]
Python files in [project] need to be able to read configuration data from the 'conf' directory, but I cannot guarantee the location of root, plus it may be used on both Linux, Mac and Windows machines so I am trying to relatively address the conf directory from the root directory.
At the minute it's working with a dirty hack (from root/bin, particular python filename is 8 chars long):
path = os.path.abspath(__file__)[:-8]
os.chdir(path)
os.chdir("..")
[projectclass].config('config/scans.json') #for example
But this is particularly horrid and is giving me nightmares. Is there a better way to accomplish what I'm trying to achieve that doesn't feel so dirty? I feel like I'm missing something very obvious. Thanks in advance.

Instead of:
path = os.path.abspath(__file__)[:-8]
use:
path = os.path.dirname(os.path.abspath(__file__))
See the docs here.