Batch Scripting-Python - python

I am new to python, I am creating an application which requires multiple batch files to be generated. There are only few minor differences in every batch files. Is there any way i can create a batch file using code?

Yes, you can
A Batch file is just a normal text file, which is executable. In order to get the File executable, you need to:
Set File permissions, (On Linux via chmod +x)
Tell the computer how to execute the file, this is done via the file ending on Windows and via the Shebang on Unix systems
Now, that we have coverd the basics, We can look at how to create the file.
since you say, you're files are very similar you should create a template for your file.
This can be done using a Docstring, or a separate file, it is important however, that you replace all positions in the file, where you want a custom value by {}.
Using this template you can use the format mini-language inorder to generate your file.
In python pseudo-code this will look like this:
template = """#/bin/bash/ \n My template with {} specification and {} specification"""
spec_1 = "example"
spec_2 = "present"
with open('my_batch_file', 'w') as file:
file.write(template.format(spec_1, spec_2))

Related

Archive files directly from memory in Python

I'm writing this program where I get a number of files, then zip them with encryption using pyzipper, and also I'm using io.BitesIO() to write these files to it so I keep them in-memory. So now, after some other additions, I want to get all of these in-memory files and zip them together in a single encrypted zip file using the same pyzipper.
The code looks something like this:
# Create the in-memory file object
in_memory = BytesIO()
# Create the zip file and open in write mode
with pyzipper.AESZipFile(in_memory, "w", compression=pyzipper.ZIP_LZMA, encryption=pyzipper.WZ_AES) as zip_file:
# Set password
zip_file.setpassword(b"password")
# Save "data" with file_name
zip_file.writestr(file_name, data)
# Go to the beginning
in_memory.seek(0)
# Read the zip file data
data = in_memory.read()
# Add the data to a list
files.append(data)
So, as you may guess the "files" list is an attribute from a class and the whole thing above is a function that does this a number of times and then you get the full files list. For simplicity's sake, I removed most of the irrelevant parts.
I get no errors for now, but when I try to write all files to a new zip file I get an error. Here's the code:
with pyzipper.AESZipFile(test_name, "w", compression=pyzipper.ZIP_LZMA, encryption=pyzipper.WZ_AES) as zfile:
zfile.setpassword(b"pass")
for file in files:
zfile.write(file)
I get a ValueError because of os.stat:
File "C:\Users\vulka\AppData\Local\Programs\Python\Python310\lib\site-packages\pyzipper\zipfile.py", line 820, in from_file
st = os.stat(filename)
ValueError: stat: embedded null character in path
[WHAT I TRIED]
So, I tried using mmap for this purpose but I don't think this can help me and if it can - then I have no idea how to make it work.
I also tried using fs.memoryfs.MemoryFS to temporarily create a virtual filessystem in memory to store all the files and then get them back to zip everything together and then save it to disk. Again - failed. I got tons of different errors in my tests and TBH, there's very little information out there on this fs method and even if what I'm trying to do is possible - I couldn't figure it out.
P.S: I don't know if pyzipper (almost 1:1 zipfile with the addition of encryption) supports nested zip files at all. This could be the problem I'm facing but if it doesn't I'm open to any suggestions for a new approach to doing this. Also, I don't want to rely on a 3rd party software, even if it is open source! (I'm talking about the method of using 7zip to do all the archiving and ecryption, even though it shouldn't even be possible to use it without saving the files to disk in the first place, which is the main thing I'm trying to avoid)

Python - generate filename from supplied pattern

Before I get too far into making my own module, I wanted to ask if there is already something like this available. I'm making an application that creates output files from input files, and I would like the ability to name the output file based on a configurable template. For instance, the template might look like the following:
"Output_"<DATE:YYYYMMDD>"_"<DATE:HHMMSS>".txt"
to create files like Output_20190606_130612.txt
or it might look like:
<SEQUENCE:00-99>"-"<DATE:YYYYMMDD>".dat"
to create files like 13_20190606.dat
Is there any module in Python that already has this functionality?
EDIT:
The template will be user-configurable, e.g. in a configuration file that the main application reads. The template will be a combination of fixed strings and fields that will be populated by the application, but the application won't know ahead of time which fields will be used in the configuration.
You can simply create a template string like this
template = "Output_{YYYYMMDD}_{HHMMSS}.txt"
And then when saving the file format the string
file_name = template.format(YYYYMMDD="20190606", HHMMSS="130612")

Python in SPSS - KEEP variables

I have selected the variables I need based on a string within the variable name. I'm not sure how to keep only these variables from my SPSS file.
begin program.
import spss,spssaux
spssaux.OpenDataFile(r'XXXX.sav')
target_string = 'qb2'
variables = [var for var in spssaux.GetVariableNamesList() if target_string in var]
vars = spssaux.VariableDict().expand(variables)
nvars=len(vars)
for i in range(nvars):
print vars[i]
spss.Submit(r"""
SAVE OUTFILE='XXXX_reduced.sav'.
ADD FILES FILE=* /KEEP \n %s.
""" %(vars))
end program.
The list of variables that it prints out is correct, but it's falling over trying to KEEP them. I'm guessing it's something to do with not activating a dataset or bringing in the file again as to why there's errors?
Have you tried reversing the order of the SAVE OUTFILE and ADD FILES commands? I haven't run this in SPSS via Python, but in standard SPSS, your syntax will write the file to disk, and then select the variables for the active version in memory--so if you later access the saved file, it will be the version before you selected variables.
If that doesn't work, can you explain what you mean by falling over trying to KEEP them?
It appears that the problem has been solved, but I would like to point out another solution that can be done without writing any Python code. The extension command SPSSINC SELECT VARIABLES defines a macro based on properties of the variables. This can be used in the ADD FILES command.
SPSSINC SELECT VARIABLES MACRONAME="!selected"
/PROPERTIES PATTERN = ".*qb2".
ADD FILES /FILE=* /KEEP !selected.
The SELECT VARIABLES command is actually implemented in Python. Its selection criteria can also include other metadata such as type and measurement level.
You'll want to use the ADD FILES FILE command before the SAVE for your saved file to be the "reduced" file
I think your very last line in the python program should be trying to join the elements in the list vars. For example: %( " ".join(vars) )

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

Apple Automator process csv files and create new files

Is it possible to loop through a set of selected files, process each, and save the output as new files using Apple Automator?
I have a collection of .xls files, and I've gotten Automator to
- Ask for Finder Items
- Open Finder Items
- Convert Format of Excel Files #save each .xls file to a .csv
I've written a python script that accepts a filename as an argument, processes it, and saves it as p_filename in the directory the script's being run from. I'm trying to use Run Shell Script with the /usr/bin/python shell and my python script pasted in.
Some things don't translate too well, though, especially since I'm not sure how it deals with python's open('filename','w') command. It probably doesn't have permissions to create new files, or I'm entering the command incorrectly. I had the idea to instead output the processed file as text, capture it with Automator, and then save it to a new file.
To do so, I tried to use New Text File, but I can't get it to create a new text file for each file selected back in the beginning. Is it possible to loop through all the selected Finder Items?
Why do you want this done in the folder of the script? Or do you mean the folder of the files you are getting from the Finder items? In that case just get the path for each file passed into Python.
When you run open('filename','w') you should thus pass in a full pathname. Probably what's happening is you are actually writing to the root directory rather than where you think you are.
Assuming you are passing your files to the shell command in Automator as arguments then you might have the following:
import sys, os
args = sys.argv[1:]
for a in args:
p = os.path.dirname(a)
mypath = p + "/" + name
f = open(mypath, "w")

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