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String Concatenation in Python: Using the + Operator, f-strings, and join()
In Python, you often need to combine multiple strings into a new one. Examples include combining a first and last name to create a full name, or assembling a log message. There are several ways to concatenate strings, such as the + opera... -
Python Escape Sequences: How to Use \n (Newline), \t (Tab), and \ (Backslash)
In Python, strings are enclosed in single quotes (') or double quotes ("). However, sometimes you want to include the quote itself within the string (like "It's"), or insert special control characters like newlines or tabs. Writing them ... -
Python String (str) Type: Basics, Quotes, and Multi-line Strings
In Python, the string (str) is one of the most frequently used data types. It is used to handle text data such as greetings like "Hello", user IDs, filenames, or error messages. A string is treated as a "sequence of characters." This art... -
Handling Infinity (inf) and Not a Number (nan) in Python: float and math module
Python's float type can represent special states like "Infinity" and "Not a Number" in addition to standard numbers like 3.14 or -0.5. These are used in mathematical calculations (like division by zero attempts) or when handling missing ... -
Python Floating Point (float) Type: Basics, E-notation, and Calculation Errors
In Python, besides integers (int) like 10 or -5, we often need to handle numbers with decimal points like 3.14 or 0.5. These are called Floating Point Numbers (float).float is essential for many programming tasks, such as scientific calc... -
Python Boolean Operators: Usage of and, or, not and Short-Circuit Evaluation
When handling conditional branches like if statements in Python, you often want to combine multiple conditions. For example, "User is authenticated AND is an administrator" or "Process failed OR timed out." To achieve this, Python provid... -
Python Chained Comparison Operators: How to use a < b < c
When writing programs in Python, we often want to check if a value is within a specific range. For example, "Is the score 80 or more AND less than 100?" In many programming languages, you must use the and operator to write this logic: (8... -
Python Comparison Operators: The 6 Basics and How to Use Them
When using if statements to control the flow of a program, you often need to compare the relationship between two values. For example, "Is the variable greater than 100?" or "Does the input password match the saved one?" Comparison opera... -
Python’s Boolean Type (bool): Basic Usage of True and False
In programming, we often need to decide if a specific condition is "Right (True)" or "Wrong (False)." Python provides a dedicated data type for these two states: the Boolean type (bool). The bool type has only two values: True and False.... -
Basics of Python Integer Type (int): Usage and Notes on Numeric Literals
The "Integer type" (int) in Python is one of the most frequently used data types in programming. It refers to numbers without decimal points: positive integers, negative integers, and zero (0). This article explains the basic usage of th... -
Correct Usage of None in Python: Checking for “No Value”
In programming, there are times when you want to explicitly indicate that a variable "has not been set yet" or "relevant data does not exist." Python provides a special object called None for this purpose, which corresponds to null or ni... -
What are Python Reserved Words (Keywords)? Why You Can’t Use Them as Variable Names and Examples
When programming in Python, you can generally name variables, functions, and classes freely. However, there is one exception: words that are "reserved" for Python's syntax itself, known as Reserved Words (Keywords). These words are used ... -
Major Python Data Types and Variable Properties (Mutable vs. Iterable)
Python is a "dynamically typed" language, meaning you do not need to explicitly declare the type of a variable. However, the data held by a variable has a clear "Type." The data type defines what kind of data it is (integer, string, list... -
Python Variables: Basics, Naming Rules, and Avoiding Keywords
In programming, a "variable" is like a "named container" used to temporarily store data such as numbers or strings. In Python, using variables is very simple. This article explains the basic usage of variables in Python and the naming ru... -
Building and Managing Virtual Environments with venv
When working on multiple Python projects, you might face a situation like this: "Project A needs Library X version 1.0, but Project B needs version 2.0." If you only have one system-wide Python installation, these dependency conflicts be... -
Python Package Management: Basic Usage of pip and Environment Setup (install, uninstall, requirements.txt)
One of Python's greatest strengths is its rich ecosystem of "external libraries (packages)" for data analysis, web development, and automation. The standard tool used to manage (install, uninstall, version control) these packages is pip.... -
How to Color Python print() Output [ANSI, Colorama]
When displaying the results of a Python script in the terminal, coloring the output by log level (Error, Warning, Success) makes it much easier to read. There are two main ways to color print() output: Using ANSI escape sequences directl... -
Controlling Output of Python print(): How to Use sep and end Arguments
Python's print() function is frequently used to check execution results or variable contents. By default, print() separates multiple arguments with a space and automatically adds a newline at the end. However, sometimes you might want to... -
Basic Python Code Structure: Indentation, Control Flow, Functions, and Execution Blocks
Python is widely supported because its grammar is simple and easy to read. This "readability" is enforced by strict rules regarding indentation. While many other programming languages use curly braces {} to define a "block" of code, Pyth... -
How to Start and Use Python Interactive Mode (REPL)
When learning Python or testing how a library works, it is useful to run code immediately without creating a .py file. Python provides "Interactive Mode (REPL)" for this purpose. REPL stands for Read, Eval, Print, Loop. It reads your inp... -
How to Run Python Code: Scripts vs. Interactive Mode
Python is used in many development fields and data analysis because it is easy to read and versatile. There are two main ways to run Python code: creating a script file (.py) or using "Interactive Mode" (REPL) to run code line by line. T... -
Generating Random Numbers in Python: random, uniform, and randint
We often need "random numbers" for simulations, game development, or creating test data. Python has a standard library called the random module for this purpose. With this module, you can easily generate random numbers, such as decimals ... -
Pythonで乱数を生成する：random, uniform, randint関数の使い方とリスト生成
シミュレーション、ゲーム開発、あるいはテストデータの作成において、「ランダムな数値（乱数）」が必要になる場面は多々あります。 Pythonには、乱数を生成するための標準ライブラリとして random モジュール が用意されています。これを使えば、0から1... -
Pythonで三角関数(sin, cos, tan)を計算する：mathモジュールの使い方とラジアン変換
物理シミュレーション、統計処理、あるいはゲーム開発におけるキャラクターの移動制御など、プログラミングにおいて三角関数（サイン、コサイン、タンジェント）が必要になる場面は多々あります。 Pythonの標準ライブラリ math モジュールを使用すれば、こ... -
Pythonで対数関数（log）を計算する：math.log, log10, log2の使い方と使い分け
データのスケーリングや情報量の計算、物理学的な公式の実装において、対数（ロガリズム）の計算は欠かせません。 Pythonの標準ライブラリ math モジュールには、対数を計算するための関数として、汎用的な log() のほかに、底（base）があらかじめ決まっ... -
Pythonで指数関数を計算する：math.exp()の使い方とシグモイド関数の実装
科学技術計算や機械学習の分野では、ネイピア数 $e$（自然対数の底、約2.718）を底とする指数関数 $y = e^x$ が頻繁に登場します。 Pythonの標準ライブラリ math モジュールには、この計算を高速かつ高精度に行うための関数 math.exp() が用意されています... -
Pythonのmathモジュール入門：円周率(pi)やネイピア数(e)などの定数と関数の使い方
科学技術計算や幾何学的なプログラムを作成する際、円周率（$\pi$）やネイピア数（$e$）といった数学定数は頻繁に使用されます。 Pythonの標準ライブラリである math モジュール を使用すると、これらの定数を高精度で利用できるほか、平方根や三角関数な... -
Pythonで商と剰余を計算する方法：算術演算子とdivmod関数の使い分け
プログラミングにおいて、「割り算の答え（商）」と「その余り（剰余）」を求めたい場面は頻繁にあります。例えば、秒数を「何分何秒」に変換したり、アイテムを均等に配った余りを計算したりするケースです。 Pythonでは、算術演算子を使って個別に計算す... -
Pythonでべき乗（N乗）を計算する方法：**演算子とpow()関数の違いと使い分け
科学技術計算や幾何学的な計算（面積や体積など）において、ある数値を2乗、3乗、あるいはN乗したい場面は頻繁に訪れます。 Pythonには、べき乗を計算するための標準的な手段として、** 演算子と、組み込み関数の pow() が用意されています。これらは似た... -
Gemini利用時に「エラー発生しました(13)」と表示される原因と解決方法
「エラー発生しました(13)」の技術的な意味 GeminiなどのAIチャットサービスを利用している際に、「エラー発生しました(13)」というメッセージが表示され、応答が生成されなくなるケースがあります。 この「13」という数字は、Googleのサービス内部で通信...
