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…
Comparing Python Hashes
I want to compare a hash of my password to a hash of what the user typed in, with (str)(hashlib.md5(pw.encode(‘utf-8′)).hexdigest()). The hash of the password is b’¥_ÆMÐ1;2±*öªÝ=’. However, when I run the above code, I get b’xa5x83_xc6x85Mxd01;2xb1*xf6xaaxdd=’. For this rea…
Dropping Multiple Columns from a dataframe
I know how to drop columns from a data frame using Python. But for my problem the data set is vast, the columns I want to drop are grouped together or are basically singularly spread out across the column heading axis. Is there a shorter way to slice or drop all the columns with fewer lines of code rather tha…
Why can list comprehension select columns of a matrix?
Why can the list comprehension select the columns of a matrix? I am a bit confused by the for-loop. Obviously the below codes give the right answer, but why is that? Because in each iteration, the for-loop takes in a whole row instead of a number? Answer If you think about it, you are looping over the list an…
pymongo auth failed in python script
I have installed mongodb and enabled auth. and its working find. I can connect it from remote notebook using robomongo application: and We can connect from server shell locally using: Everything works fine, but when we try it using pymongo api. authentications failed. below is the python code: Tools used: Err…
Python: how to mock a kafka topic for unit tests?
We have a message scheduler that generates a hash-key from the message attributes before placing it on a Kafka topic queue with the key. This is done for de-duplication purposes. However, I am not sure how I could possibly test this deduplication without actually setting up a local cluster and checking that i…
pandas concat generates nan values
I am curious why a simple concatenation of two dataframes in pandas: of the same shape and both without NaN values can result in a lot of NaN values if joined. How can I fix this problem and prevent NaN values being introduced? Trying to reproduce it like failed e.g. worked just fine as no NaN values were int…
Searching any tree in Python
I need to write a function in Python that takes a tree and an index and returns the subtree or leaf at that index. I tried with loops and nested loops until I realized that the tree that had to run the tests was always the same: which actually looks like this: Sample tree So all I needed to pass
How to define enum values that are functions?
I have a situation where I need to enforce and give the user the option of one of a number of select functions, to be passed in as an argument to another function: I really want to achieve something like the following: So the following can be executed: Answer Your assumption is wrong. Values can be arbitrary,…
python – prefix sum algorithm
I am trying to grasp the idea behind the prefix sum concept looking at the example presented in the Prefix Sum Lesson by Codility here (The mushroom picker problem) My understanding is that the whole concept is based on the simple property where for finding a sum of all elements between two positions A(pos_le…