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In programming, you often need to convert decimal numbers into formats that computers interpret easily, such as binary, or formats used in memory dumps, such as hexadecimal. Python provides convenient built-in functions to convert number...

When handling numbers in Python programs, we usually use decimal numbers (0-9). However, depending on the application, it may be more intuitive to use binary, octal, or hexadecimal. For example, binary is suitable for bitwise operations,...

When outputting files, ensuring the destination directory (folder) exists beforehand is necessary. The Python standard library os module provides two functions for creating directories: os.mkdir() and os.makedirs(). os.makedirs() is part...

In file manipulation programs, deleting unnecessary temporary files or directories containing old data is often necessary. In Python, the function used differs depending on whether the target is a "file" or a "directory (folder)". This a...

Copying files or directories is essential when creating data backups or replicating template folders for new projects. The Python standard library shutil module (Shell Utilities) allows executing these operations with simple function cal...

In scenarios like organizing files, rotating logs, or processing backups, you often need to move files or directories to a different location. To do this in Python, using the move() function from the standard library shutil module is the...

In file manipulation programs, it is often necessary to branch processing based on file extensions. Common scenarios include "processing only image files (.jpg, .png)" or "excluding anything other than text files (.txt)". The Python stan...

In file manipulation programs, you often need to distinguish whether a specified path is a "file" or a "directory (folder)" to handle them differently. For example, after getting a list of items in a directory, you might want to perform ...

In file manipulation scripts, you often need to process all files inside a specific folder. There are two main ways to get a list of contents in a directory in Python: pathlib module (Recommended): An object-oriented, modern approach int...

Before performing file operations, checking "if the file is really there" is very important to prevent errors like FileNotFoundError. The Python standard library os.path module provides several functions to check for existence. You need ...

In programs that perform file operations, we use a "Path" to specify the file location. There are two types of paths: "Absolute Path," which describes the location from the root directory, and "Relative Path," which describes the locatio...

When reading or writing files in a Python script using relative paths (e.g., data.txt), the program searches for them based on the "Current Directory (Current Working Directory)." Therefore, knowing where your program is currently runnin...

In programs handling file paths, operations like "extracting just the filename from a full path" or "getting the parent directory path excluding the filename" are frequent. Python's standard library os.path module provides the split() fu...

When handling file or directory paths in a program, concatenating directory names and file names to create a single path string is a frequent operation. While it is possible to simply add strings (+) or use the join method with /, this c...

When trying to run Python scripts on both Windows and macOS (or Linux), the difference in "file path separators" often becomes a problem. Windows: Backslash \ (written as \\ in Python strings) macOS / Linux: Forward slash / If you hardco...

When saving calculation results or log data to a file in Python, you open the file in "write mode" using the built-in function open() and use methods to write the data. There are two methods for writing: write(), which writes a single st...

When reading the contents of a text file in Python, you use the built-in open() function. There are three main methods for "extracting data" afterwards: read(): Reads the entire content as a single string. readlines(): Reads the entire c...

When dealing with text or binary files in Python, use the built-in function open(). This function creates a file object by specifying a "mode" such as reading, writing, or appending. Also, in file operations, you must close the file (rel...

While Python is a language that handles memory management automatically (it has garbage collection), excessive memory usage can become a problem in processes handling large data or long-running server applications. In such cases, you can...

When evaluating program performance, accurately measuring "how long a process took" is crucial. Python's standard library time module provides several functions for measuring time, but you need to select the appropriate one depending on ...

When using Python type hints, you encounter cases where "this variable might contain an integer or a string" or "the data type cannot be specified." To handle such flexible type definitions, Python provides the Union type (or | operator)...

When defining collection variables like lists (list) or dictionaries (dict) in Python, simply writing items: list is often not enough. Without information like "I know it's a list, but does it contain numbers or strings?", there is a ris...

Python is a "dynamically typed language," meaning you can write code without declaring variable types (integer, string, etc.). While this flexibility is appealing, it can cause confusion in large-scale or team development, such as "What ...

Unlike sys.argv, which simply receives command-line arguments as a list, using Python's standard library argparse allows you to easily implement advanced features such as "automatic help message generation," "argument type checking," and...

Python has a "recommended way of writing" called "Pythonic," which leverages features and conventions unique to Python. Bringing habits from other programming languages or continuing to write verbose code is called an "Anti-pattern," whi...

Python is a language designed with a focus on "readability." To ensure that code looks consistent regardless of who writes it, the Python community follows a standard coding convention called "PEP 8". This article explains what PEP is an...

Separating configuration information (such as database connection details, debug mode flags, and timeout settings) into external files is a fundamental practice in software development. Python provides a standard library called configpar...

Test code created with unittest can be executed not only directly as a Python script (writing if __name__ == "__main__":), but also more flexibly using the python -m unittest command from the command line. Using this command allows you t...

When performing unit tests, you often need "pre-processing" such as connecting to a database or preparing initial data before running tests. You also need "post-processing" to delete temporary files or close connections after tests finis...

To maintain high-quality code, "testing" is essential to verify that the functions and classes you create work as intended. Python comes with the unittest module as a standard library, allowing you to perform full-scale unit testing with...