Tag: python

how can i safely write to a file when using Flask?

I need to write a method on a Flask server which will write part of the request to a log file. However, if I understand correctly, Flask is multi-threaded, and there’s a good chance that writing to a file is not safe. Admittedly, I am more or less new to Python and multi-threaded programming in general,…

How to check whether screen is off in Mac/Python?

macos python

How do I check whether the screen is off due to the Energy Saver settings in System Preferences under Mac/Python? Answer Quick and dirty solution: call ioreg and parse the output. In my computer, the value for CurrentPowerState is 4 when the screen is on and 1 when the screen is off. Better solution: use ctyp…

MySQLdb install error – _mysql.c:44:23: error: my_config.h: No such file or directory

django mysql-python python

I’m trying to install MySQLdb extension, but I get this error any idea what may be the cause? Could be something with permissions? I’m using Mac OX Lion…. This is a part of the error a got. Django is installed fine, but I need to install this extension. Thanks for any help. Answer usually wh…

Find a value within nested json dictionary in python

dictionary nested python python-2.7

From the following json, in python, I’d like to extract the value “TEXT”. All the keys are constant except for unknown. Unknown could be any string like “a6784t66” or “hobvp*nfe”. The value of unknown is not known, only that it will be in that position in each json re…

python tkinter with threading causing crash

python tkinter

I have written a python tkinter code using threads so as the tkinter wizard updates automatically by tkinter mainloop running in the main thread and background process running in separate thread. But I noticed, that python crashes after some time when running the code. Moreover its random in nature but python…

Creating your own contour in opencv using python

contour image-processing numpy opencv python

I have a set of boundary points of an object. I want to draw it using opencv as contour. I have no idea that how to convert my points to contour representation. To the same contour representation which is obtained by following call Any ideas? Thanks Answer By looking at the format of the contours I would thin…

Filter an evaluated QuerySet in Django

django python

The requirement is for me to be able to access members of an evaluated QuerySet by a string attribute, in this case name. I don’t like the idea of looping over a QuerySet as it seems like there is a more efficient way. After I’ve called something like: And I evaluate it with something like: What i…

Convert image from PIL to openCV format

image-processing opencv python python-imaging-library

I’m trying to convert image from PIL to OpenCV format. I’m using OpenCV 2.4.3. here is what I’ve attempted till now. But I think the image is not getting converted to CV format. The Window shows me a large brown image. Where am I going wrong in Converting image from PIL to CV format? Also , …

Relative imports for the billionth time

import python python-packaging relative-import relative-path

I’ve been here: http://www.python.org/dev/peps/pep-0328/ http://docs.python.org/2/tutorial/modules.html#packages Python packages: relative imports python relative import example code does not work Relative imports in python 2.5 Relative imports in Python Python: Disabling relative import and plenty of U…