Text Formatting and Headings in HTML

<section class="documentation">
    <h2>Python String Formatting</h2>
    
    <p>Python provides several methods for formatting strings. This guide covers the most common approaches.</p>
    
    <h3>f-Strings (Python 3.6+)</h3>
    
    <p><dfn>f-strings</dfn> (formatted string literals) provide a concise and readable way to include expressions inside string literals.</p>
    
    <pre><code>name = "Alice"
age = 30
message = f"Hello, {name}! You are {age} years old."
print(message)  # Output: Hello, Alice! You are 30 years old.</code></pre>
    
    <p>You can include expressions inside the curly braces:</p>
    
    <pre><code>price = 49.95
quantity = 3
total = f"Total: ${price * quantity:.2f}"
print(total)  # Output: Total: $149.85</code></pre>
    
    <h3>The <code>format()</code> Method</h3>
    
    <p>Before f-strings, the <code>str.format()</code> method was the preferred way to format strings:</p>
    
    <pre><code>name = "Bob"
age = 25
message = "Hello, {}! You are {} years old.".format(name, age)
print(message)  # Output: Hello, Bob! You are 25 years old.</code></pre>
    
    <p>You can use numbered placeholders to rearrange arguments:</p>
    
    <pre><code>message = "The {1} contains {0}.".format("fruit", "basket")
print(message)  # Output: The basket contains fruit.</code></pre>
    
    <div class="note">
        <p><strong>Note:</strong> While the <code>%</code> operator (e.g., <code>"Hello, %s" % name</code>) still works, it's considered outdated and not recommended for new code.</p>
    </div>
    
    <h3>Common Formatting Specifiers</h3>
    
    <p>Both f-strings and <code>format()</code> use similar formatting specifiers:</p>
    
    <ul>
        <li><code>{variable:.2f}</code> - Float with 2 decimal places</li>
        <li><code>{variable:10s}</code> - String with a minimum width of 10 characters</li>
        <li><code>{variable:<10}</code> - Left-aligned with a width of 10</li>
        <li><code>{variable:>10}</code> - Right-aligned with a width of 10</li>
        <li><code>{variable:^10}</code> - Center-aligned with a width of 10</li>
        <li><code>{variable:,}</code> - Number with thousand separators</li>
    </ul>
    
    <p>To format a variable <var>x</var> with both alignment and precision, use: <code>{x:&gt;10.2f}</code></p>
    
    <p>For more information, type <kbd>help('FORMATTING')</kbd> in a Python interactive shell.</p>
</section>