I have a python program that loads preferences from another .py file.
And I need to implement a way to update this preferences on the way.
I've been using text files and reading it, and then, use a template, format it, save it and reading again to load the preferences variables. But when I add a new parameter I need to reformat and rewrite the functions that read, format and write.
So I think a better way to do this is with .py files to load. But I don't know if there's a way to modify this variables and save the .py file while using it.
Any idea or solution to this?
Related
I am wondering if there is an easy way to access 'parallel' directories (See photo for what I am talking about... I don't know what else to call them, please correct me if they are called something else!) from a Python file without having to input the string path.
The basic structure I intend to use is shown in the picture. The structure will be used across different computers, so I need to avoid just typing in "C:\stuff_to_get_there\parent_directory\data\file.txt" because "C:\stuff_to_get_there" will not be the same on different computers.
I want to store the .py files in their own directory, then access the data files in data directory, and save figures to figures directory. I was thinking of trying os module but not sure if that's the correct way to go.
parent directory
scripts
.py files
figures
save files here
data
.txt files stored here
Thanks for any help!
A python package that I'm using has data stored under a single file with a .pkz extension. How would I unzip (?) this file to view the format of data within?
Looks like what you are referencing is just a one-off file format used in sample data in scikit-learn. The .pkz is just a compressed version of a Python pickle file which usually has the extension .pkl.
Specifically you can see this in one of their sample files here along with the fact they are using the zlib_codec. To open it, you can go in reverse or try uncompressing from the command line.
Before attempting to open an PKZ file, you'll need to determine what kind of file you are dealing with and whether it is even possible to open or view the file format.
Files which are given the .PKZ extension are known as Winoncd Images Mask files, however other file types may also use this extension. If you are aware of any additional file formats that use the PKZ extension, please let us know.
How to open a PKZ file:
The best way to open an PKZ file is to simply double-click it and let the default assoisated application open the file. If you are unable to open the file this way, it may be because you do not have the correct application associated with the extension to view or edit the PKZ file.
If you can do it, great, you have a program installed that can do it, lets say that program is called pkzexecutor.exe, with python, you just have to do:
import subprocess
import os
path_to_notepad = 'C:\\Windows\\System32\\pkzexecutor.exe'
path_to_file = 'C:\\Users\\Desktop\\yourfile.pkz'
subprocess.call([path_to_notepad, path_to_file])
From the source code for fetch_olivetti_faces, the file appears to be downloaded from http://cs.nyu.edu/~roweis/data/ and originally has a .mat file extension, meaning it is actually a MATLAB file. If you have access to MATLAB or another program which can read those files, try opening it from there with the original file extension and see what that gives you.
(If you want to try opening this file in Python itself, then perhaps give this question a look: Read .mat files in Python )
I'm looking to store some individual settings to each user's computer. Things like preferences and a license key. From what I know, saving to the registry could be one possibility. However, that won't work on Mac.
One of the easy but not so proper techniques are just saving it to a settings.txt file and reading that on load.
Is there a proper way to save this kind of data? I'm hoping to use my wx app on Windows and Mac.
There is no proper way. Use whatever works best for your particular scenario. Some common ways for storing user data include:
Text files (e.g. Windows INI, cfg files)
binary files (sometimes compressed)
Windows registry
system environment variables
online profiles
There's nothing wrong with using text files. A lot of proper applications uses them exactly for the reason that they are easy to implement, and additionally human readable. The only thing you need to worry about is to make sure you have some form of error handling in place, in case the user decides to replace you config file content with some rubbish.
Take a look at Data Persistence on python docs. One option a you said could be persist them to a simple text file. Or you can save your data using some serialization format as pickle (see previous link) or json but it will be pretty ineficient if you have several keys and values or it will be too complex.
Also, you could save user preferences in an .ini file using python's ConfigParser module as show in this SO answer.
Finally, you can use a database like sqlite3 which is simpler to handle from your code in order to save and retrieve preferences.
I have a simple web-server written using Python Twisted. Users can log in and use it to generate certain reports (pdf-format), specific to that user. The report is made by having a .tex template file where I replace certain content depending on user, including embedding user-specific graphs (.png or similar), then use the command line program pdflatex to generate the pdf.
Currently the graphs are saved in a tmp folder, and that path is then put into the .tex template before calling pdflatex. But this probably opens up a whole pile of problems when the number of users increases, so I want to use temporary files (tempfile module) instead of a real tmp folder. Is there any way I can make pdflatex see these temporary files? Or am I doing this the wrong way?
without any code it's hard to tell you how, but
Is there any way I can make pdflatex see these temporary files?
yes you can print the path to the temporary file by using a named temporary file:
>>> with tempfile.NamedTemporaryFile() as temp:
... print temp.name
...
/tmp/tmp7gjBHU
As commented you can use tempfile.NamedTemporaryFile. The problem is that this will be deleted once it is closed. That means you have to run pdflatex while the file is still referenced within python.
As an alternative way you could just save the picture with a randomly generated name. The tempfile is designed to allow you to create temporary files on various platforms in a consistent way. This is not what you need, since you'll always run the script on the same webserver I guess.
You could generate random file names using the uuid module:
import uuid
for i in xrange(3):
print(str(uuid.uuid4()))
The you save the pictures explictly using the random name and pass insert it into the tex-file.
After running pdflatex you explicitly have to delete the file, which is the drawback of that approach.
I'm working on a online server, and I need all my list and dict saved. What would be the best and quickest way to approach this?
I tried importing the data, and it works to load the data. But how can I update the imported file?
I think you can use pickle/cPickle module to save and load the date, which are built-in module and easy to use.
I am not very sure the meaning of update import file, what about rewrite the content back to the file after updating in the program?