Recently, I learned art of string formatting in Python 2.7. I decided to play with floating point numbers. Came across an awkward looking solution, as written below. BUT Please help me understand, why this behavior is shown by %f. Answer The internal implementation for the %.0f string format uses a round-half-even rounding mode. In Python 2, the round() function uses
Get the value of a checkbox in Flask
I want to get the value of a checkbox in Flask. I’ve read a similar post and tried to use the output of request.form.getlist(‘match’) and since it’s a list I use [0], but it seems I’m doing something wrong. Is this the correct way to get the output or is there a better way? Answer You don’t need to use
Plotting a NACA 4-series airfoil
I’m trying to plot an airfoil from the formula as described on this wikipedia page. This Jupyter notebook can be viewed on this github page. The result looks like . I expected it to look more like . Questions: Why is the line not completely smooth? There seems to be a discontinuity where the beginning and end meet. Why does
Exclude a directory from getting zipped using zipfile module in python
I am trying to zip a directory using python zipfile module and its working well.But now i want to exclude some folders.ie if my director tree is like then i want to archive all to myfile.zip but excluding “ghi” I am trying to zip files using so this is archiving everything under “D:review docs” to “Application server.zip” but i want
Python in-memory cache with time to live
I have multiple threads running the same process that need to be able to to notify each other that something should not be worked on for the next n seconds its not the end of the world if they do however. My aim is to be able to pass a string and a TTL to the cache and be able
Separating development and production parts of django project
I’m building a site that relies on the output of a machine learning algorithm. All that is needed for the user-facing part of the site is the output of the algorithm (class labels for a set of items), which can be easily stored and retrieved from the django models. The algorithm could be run once a day, and does not
How can I open a website in my web browser using Python?
I want to open a website in my local computer’s web browser (Chrome or Internet Explorer) using Python. Is there a module that can do this for me? Answer The webbrowser module looks promising: https://www.youtube.com/watch?v=jU3P7qz3ZrM
Convert commas decimal separators to dots within a Dataframe
I am importing a CSV file like the one below, using pandas.read_csv: Example of CSV file: The problem is that when I later on in my code try to use these values I get this error: TypeError: can’t multiply sequence by non-int of type ‘float’ The error is because the number I’m trying to use is not written with a
Iterating over lines in a file python
I have seen these two ways to process a file: I know that in the first case, the file will act like a list, so the for loop iterates over the file as if it were a list. What exactly happens in the second case, where we read the file and then iterate over the contents? What are the consequences
Tkinter import filedialog error
I’m trying to use tkinter with python3 to open an image, see here a piece of code : I have installed python3-tk, and I have the demo window when I write in the terminal. I tried several combinations that did not work : gives , gives I tried with _tinker , FileDialog, file_dialog, but I always have “ImportError : cannot