Programming Leftovers

posted by Roy Schestowitz on Jul 30, 2023

• Posit Package Manager for Linux R Binaries

  I’ve been getting a lot of use recently from the Posit (née RStudio) Package Manager (PPM), because it offers freely available R package binaries for quite a few Linux...
  

• Grover’s algorithm with qsimulatR

  Cover photo by gorodenkoff on iStock
  This is the third article of the Quantum Computing simulation with R series.
  

• Debugging the keyboard navigation in your QML application

  A neat trick to debug the keyboard navigation in your QML application is to put the following code snippet in your main.qml: [...]

• Linux Plumbers Conference: Rust MC CFP

  LPC 2023 will host the second edition of the Rust MC. This microconference intends to cover talks and discussions on both Rust for Linux as well as other non-kernel Rust topics. Proposals can be submitted via LPC submission system, selecting the Rust MC track.

  Rust is a systems programming language that is making great strides in becoming the next big one in the domain. Rust for Linux is the project adding support for the Rust language to the Linux kernel.

  Rust has a key property that makes it very interesting as the second language in the kernel: it guarantees no undefined behavior takes place (as long as unsafe code is sound). This includes no use-after-free mistakes, no double frees, no data races, etc. It also provides other important benefits, such as improved error handling, stricter typing, sum types, pattern matching, privacy, closures, generics, etc.

• Python Rename File

  By using the “os.rename()” function, “shutil.move()” function, or using the “os” module, users can rename a single or bulk of files using Python.

• Python os.path example

  In Python, the “os.path” module of the “os” library provides several functions to work with specified paths in various operating systems.

• Python Random Shuffle Method

  The “random.shuffle()” method of the “random” module is used to shuffle a list of strings or a list of integers in Python.

• Tkinter Grid

  The tkinter grid is a two-dimensional table with rows and columns, where each cell can hold a widget such as buttons, labels, or entry fields.

• Get the Pandas DataFrame Rows Based on Index

  The “DataFrame.iloc[]” and the “DataFrame.loc[]” method of the “Pandas” module is used to get the Pandas DataFrame rows based on the index.

• Seaborn HeatMap Colors

  The “seaborn.heatmap()” function of the “Seaborn” module is utilized in Python to plot/create rectangular data in the color-coded matrix form.

• How to Catch All Exceptions in Python

  The “try” and “except” statement, the “raise” exception, and the “logger.exception” method is used to catch all exceptions in Python.

• Python OS Environ

  The “os.environ” is a mapping object or built-in dictionary in Python that represents all the user’s environment variable values in key-value pairs set.

• Pandas DataFrame Select Rows By Condition

  The relational operators, “df.isin()”, “&” operator, and “df.loc[]” methods, are used to select DataFrame rows based on particular conditions.

• Print Stacktrace in Pyhton Log

  The “traceback” or “logging“ module provides several functions that are used in Python to log the error message and the Stacktrace.

• Pandas Distinct Values Column

  The “pandas.unique()”, “Series.unique()”, “Numpy.unique()”, and “pandas.concat()” methods are used to get distinct values of the Pandas DataFrame column.

• Tkinter Treeview

  “Tkinter-treeview” is a specialized widget in “Tkinter” that presents hierarchical data structures in a tree-like format.

• Python Priority Queue Example

  In Python, the “List”, “heapq”, and “queue.PriorityQueue” methods are used to implement Priority Queues and return data items based on their priority.

• How to find the average of a list in Python

  The average of a list in Python can be found using the iterative method, sum() and len() functions, reduce() and lambda() functions, numpy, or statistics modules.

• Pandas Append to CSV

  The “df.to_csv()” function of the Pandas module is used to append Pandas DataFrame to CSV (Comma Separated Value) file in Python.

• SciPy Matrices

  The “scipy.linalg” module and the “scipy.sparse” module of the Scipy library is used to perform various operations on Scipy matrices in Python.

• Random Integer Python

  The “random.randint()” or the “random.randrange()” methods of the “random” module are utilized to generate/create a random integer in Python:

• Python os getenv

  The “os.getenv()” method of the “os” module is utilized in Python to retrieve the environment variable key value if it is present.

• Pandas Agg Count

  The “groupby()” method splits data into groups based on columns and finds total values in a column for each group using the agg method, such as “count”.

• Pandas Add Header

  The “pd.DataFrame()” columns parameter, “DataFrame.columns” method and the “DataFrame.set_axis()” method is used to add a header to Pandas DataFrame in Python.