I have some protocol buffer definitions which need to be built to Python source as part of the pip install process. I’ve subclassed the setuptools.command.install command in setup.py but I think it’s trying to run the Makefile after the package is installed so the sources aren’t recognised. …
Tag: python
Executing multiple statements with Postgresql via SQLAlchemy does not persist changes
This does not work – the update has no effect: Switching the statements performs the update and select successfully: Why does the first not work? It works in Pgadmin. I enabled autocommit with Flask-Sqlalchemy. I am doing a workshop on SQL injection, so please dont rewrite the solution! Answer The way SQLAlch…
What does ‘# noqa’ mean in Python comments?
While searching through a Python project, I found a few lines commented with # noqa. What does noqa mean in Python? Is it specific to Python only? Answer Adding # noqa to a line indicates that the linter (a program that automatically checks code quality) should not check this line. Any warnings that code may …
How to retrieve an Enum key via variable
I’m new to python. Is it possible to get the value of an Enum key from a variable key? Answer One of the many neat features of Python’s Enums is retrieval by name: and for the value:
Keras confusion about number of layers
I’m a bit confused about the number of layers that are used in Keras models. The documentation is rather opaque on the matter. According to Jason Brownlee the first layer technically consists of two layers, the input layer, specified by input_dim and a hidden layer. See the first questions on his blog. …
Understanding free OPC/UA code in python
I am working on OPCUA in python. I am using freeopc. I have used their server_minimal & client_minimal example and it is running fine. I am having some issues understanding the code. As far as I know the OPCUA stack, it has address space which is like a collection of all the nodes. These nodes then furthe…
How to add a newline function to JSON using Python
I have a JSON that I had to manipulate and the code looks like this. I had to manipulate the data because of an invalid part of the data that I could not use when uploading to BigQuery. However out_file.write(“n”) is not making the JSON write each set of data on a newline like it has in the previo…
Athena query fails with boto3 (S3 location invalid)
I’m trying to execute a query in Athena, but it fails. Code: But it raises the following exception: However, if I go to the Athena Console, go to Settings and enter the same S3 location (for example): the query runs fine. What’s wrong with my code? I’ve used the API of several the other serv…
Join/Merge two Pandas dataframes and use columns as multiindex
I have two dataframes with KPIs by date. I want to combine them and use multi-index so that each KPI can be easily compared to the other for the two df. Like this: I have tried to extract each KPI into a series, rename the series accordingly (df1, df2), and then concatenating them using the keys argument of p…
Convert SAS data to a python dataframe
I have this small little code here to import a SAS file into dataframe in Python. The code runs forever without any output. The sas file I’m trying to import is 1.5gb. Answer You should use the native pandas function pandas.read_sas it’s faster than iterating through the file as you did. Here is t…