You could use threading.Timer, but that also schedules a one-off event, similarly to the .enter method of scheduler objects. The normal pattern (in any language) to transform a one-off scheduler into a periodic scheduler is to have each event re-schedule itself at the specified interval. For example, with sched, I would not use a loop … Read more
UPDATE: This is no longer necessary with Python3.4. It installs pip3 as part of the stock install. I ended up posting this same question on the python mailing list, and got the following answer: # download and install setuptools curl -O https://bootstrap.pypa.io/ez_setup.py python3 ez_setup.py # download and install pip curl -O https://bootstrap.pypa.io/get-pip.py python3 get-pip.py Which … Read more
The difference is that when you use from, the __cause__ attribute is set and the message states that the exception was directly caused by. If you omit the from then no __cause__ is set, but the __context__ attribute may be set as well, and the traceback then shows the context as during handling something else … Read more
Here is my workflow after creating a folder and cd‘ing into it: $ virtualenv venv –distribute New python executable in venv/bin/python Installing distribute………done. Installing pip…………….done. $ source venv/bin/activate (venv)$ python
The y in your lambda refers to the last value that y had in the scope it came from, i.e., 9. The easiest way to get the behavior you want is to use a default argument in your lambda: lambda x, y=y: x/y This captures the value of y at the moment the lambda function … Read more
This is a bit of an iPython headshot that comes with Spyder. I’ve fallen foul of this when copy/pasting random bits of code from SO to test only to find really odd behaviour several days later – variables defined in the iPython console will also be in the script’s global namespace indefinitely. There’s two things … Read more
Note that “xml package” and “the xml library” are ambiguous. There are several XML-related modules in the standard library: https://docs.python.org/3/library/xml.html. Why is it modified? ElementTree moves namespace declarations to the root element, and namespaces that aren’t actually used in the document are removed. Why does ElementTree do this? I don’t know, but perhaps it is … Read more
input takes a prompt string as its argument, which it will print automatically, but print returns None; it is this that gets printed by input. Your code is equivalent to: prompt = print(…) # prompt == None ans = int(input(prompt)) Instead, use str.format to build the prompt and pass it straight to input: ans = … Read more
The ** operator follows normal mathematical conventions; it is right-associative: In the usual computer science jargon, exponentiation in mathematics is right-associative, which means that xyz should be read as x(yz), not (xy)z. In expositions of the BODMAS rules that are careful enough to address this question, the rule is to evaluate the top exponent first. … Read more
If the image is a “mask” image, with a transparent background and a white (255, 255, 255) mask, then you can “tint” the image with ease. Load the image: image = pygame.image.load(imageName) Generate a uniform colored image with an alpha channel and the same size: colorImage = pygame.Surface(image.get_size()).convert_alpha() colorImage.fill(color) Blend the image with maskImage, by … Read more