Suppose we have the following mod.py: and the following use of it: I get an error: According to the documentation the documentation the with statement should execute as follows (I believe it fails at step 2 and therefore truncate the list): The context expression (the expression given in the with_item) is eva…
Tag: python-3.x
Django FileField not cooperating with Python 3’s csv module
I have this form: The intended purpose of import_csv() is to import the CSV to the application’s database, but it has been altered for brevity’s sake. An exception occurs when I attempt to iterate over school_csv, which I guess is when DictReader first attempts to read the file: I don’t beli…
Find longest sequence of 0’s in the integer list
A = [1,2,0,0,3,4,5,-1,0,2,-1,-3,0,0,0,0,0,0,0,0,-2,-3,-4,-5,0,0,0] Return initial and ending index of longest sequence of 0’s in the list. As, longest sequence of 0’s in above list is 0,0,0,0,0,0,0,0 so it should return 12,19 as starting and ending index.Please help with some one line python code.…
Django Admin set extra to 0 when editing
Setting extra = 1 in my model always shows a 1 empty field. It is OK while inserting a new item but I don’t want to show an additional empty field while editing. How can I do this? models.py: admin.py: Answer Override the get_extra method instead of setting a value for extra class member. Returns the nu…
Connection refused with postgresql using psycopg2
psycopg2.OperationalError: could not connect to server: Connection refused Is the server running on host “45.32.1XX.2XX” and accepting TCP/IP connections on port 5432? Here,I’ve open my sockets. I googled that I should modify this pg_hba.conf，but in my postgresqlroot files, I didn’t fi…
How to run a http server which serves a specific path?
this is my Python3 project hiearchy: From script.py, I would like to run a http server which serve the content of the web folder. Here is suggested this code to run a simple http server: but this actually serve project, not web. How can I specify the path of the folder I want to serve? Answer In Python 3.7 Si…
How to plot a figure with Chinese Characters in label
When I draw a figure with Chinese Character label in Python 3, it doesn’t work correctly: ] My code: Answer You need to explicitly pass the font properties to legend function using the prop kwag: Source
How to set coordinates when cropping an image with PIL?
I don’t know how to set the coordinates to crop an image in PILs crop(): I tried with gThumb to get coordinates, but if I take an area which I would like to crop, I can only find position 194 336. Could someone help me please? This is my picture: I wish to crop to this: Answer How to set
Infinite loop while adding two integers using bitwise operations?
I am trying to solve a problem, using python code, which requires me to add two integers without the use of ‘+’ or ‘-‘ operators. I have the following code which works perfectly for two positive numbers: This piece of code works perfectly if the input is two positive integers or two ne…
How to parse raw HTTP request in Python 3?
I am looking for a native way to parse an http request in Python 3. This question shows a way to do it in Python 2, but uses now deprecated modules, (and Python 2) and I am looking for a way to do it in Python 3. I would mainly like to just figure out what resource is requested and