I apologize in advance for asking a rather cryptic question. However, I did not understand it despite going through a lot of material. It would be great if you could shed some light on this. What is the purpose of a request_loader in flask-login? How does it interact with the user_loader decorator? If I am us…
finding out complementary/opposite color of a given color
I am trying to find out the complementary color of a given color using Python. here is my code. the code returns error message telling “AttributeError: ‘list’ object has no attribute ‘join’” I need a hint. In addition, there might be a more robust code which calculates the opposi…
Why do I get False when using issubclass in this way?
Structure: m1.py: m2.py: I don’t now why I get false while I think it’s obviously true when I run m1.py. My python version is python3.5.2. Answer Wellcome to the world of modules and namespaces! Here is what happens: In module m2, you import A from module m1. So you create a class m2.A as a refere…
Wait for complete deletion of a DynamoDB table using boto3
I need to delete a dynamodb table, and wait until it is completely removed. How can I check this? boto3 api expose a method get_waiter to wait for certain events, but it is not well documented. Can I use it for this purpose? Which would be the event name, or maybe handle a ResourceNotFoundException Answer Aft…
Extract string inside nested brackets
I need to extract strings from nested brackets like so: Result (Order doesn’t matter): Note, the string could have N brackets, and they will always be valid, but may or may not be nested. Also, the string doesn’t have to start with a bracket. The solutions I have found online to a similar problem …
Scrape information about Visit Page and App Name on google play store
I have created the code below to scrape the app name and Visit Page Url from the google play store page. ASOS – Get ASOS (Line 1120) Visit website – Get http://www.asos.com – (q=)(Line 1121 source code) I can’t seem to print the HTML here. Please open edits for that. But Please help me…
Return Excel file in Flask app
I am creating a Flask application that prompts the user for an Excel file, does some work with it, then returns the file back to the user so that they can download it. (Please ignore any unused imports. I plan on using them later on.) I have my functionality down, i’m just not sure how to send the file …
Syntax for an If statement using a boolean
I just recently joined the python3 HypeTrain. However I just wondered how you can use an if statement onto a boolean. Example: And also, can I just switch the value of a boolean like this? Answer You can change the value of a bool all you want. As for an if: works, but you can also use: If you want
Matplotlib boxplot visual styles: `whiskerprops` does not work
In the documentation of matplotlib’s boxplot we can read: whiskerprops : dict or None (default) If provided, will set the plotting style of the whiskers Ok, so I passed a dict to set some visual styles on the whiskers: The settings have no effect, except the color. Same behaviour could be observed at th…
Equality between frozensets
Example: Frozen sets are immutable. I would expect that equality between immutable objects should by determined by order, but here obviously that is not the case. How can I discard frozensets with same elements and different order, without casting to different type? Answer The short answer is you can’t,…