Python pathlib for cross-platform file operations

<p>I have Python code using os.path and string concatenation for file paths that breaks on Windows. I need to use pathlib for cross-platform file operations that work on Linux, macOS, and Windows.</p>

<p>pathlib for modern Python file operations:</p> <div class="highlight"><pre><span></span><code><span class="kn">from</span><span class="w"> </span><span class="nn">pathlib</span><span class="w"> </span><span class="kn">import</span> <span class="n">Path</span> <span class="c1"># Path construction (works on all platforms):</span> <span class="n">base_dir</span> <span class="o">=</span> <span class="n">Path</span><span class="p">(</span><span class="vm">__file__</span><span class="p">)</span><span class="o">.</span><span class="n">parent</span> <span class="n">data_dir</span> <span class="o">=</span> <span class="n">base_dir</span> <span class="o">/</span> <span class="s1">'data'</span> <span class="c1"># Uses / operator</span> <span class="n">config_file</span> <span class="o">=</span> <span class="n">base_dir</span> <span class="o">/</span> <span class="s1">'config.toml'</span> <span class="c1"># vs old style (fragile):</span> <span class="kn">import</span><span class="w"> </span><span class="nn">os</span> <span class="n">base_dir_old</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">dirname</span><span class="p">(</span><span class="vm">__file__</span><span class="p">)</span> <span class="n">config_old</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">base_dir_old</span><span class="p">,</span> <span class="s1">'config.toml'</span><span class="p">)</span> <span class="c1"># Common operations:</span> <span class="n">data_dir</span><span class="o">.</span><span class="n">mkdir</span><span class="p">(</span><span class="n">parents</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">exist_ok</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span> <span class="c1"># mkdir -p equivalent</span> <span class="n">config_file</span><span class="o">.</span><span class="n">exists</span><span class="p">()</span> <span class="c1"># File existence check</span> <span class="n">config_file</span><span class="o">.</span><span class="n">is_file</span><span class="p">()</span> <span class="c1"># Is it a file (not dir)</span> <span class="n">config_file</span><span class="o">.</span><span class="n">suffix</span> <span class="c1"># '.toml'</span> <span class="n">config_file</span><span class="o">.</span><span class="n">stem</span> <span class="c1"># 'config' (without extension)</span> <span class="n">config_file</span><span class="o">.</span><span class="n">name</span> <span class="c1"># 'config.toml'</span> <span class="n">config_file</span><span class="o">.</span><span class="n">parent</span> <span class="c1"># Path to parent directory</span> <span class="c1"># Reading and writing:</span> <span class="n">content</span> <span class="o">=</span> <span class="n">config_file</span><span class="o">.</span><span class="n">read_text</span><span class="p">(</span><span class="n">encoding</span><span class="o">=</span><span class="s1">'utf-8'</span><span class="p">)</span> <span class="n">bytes_data</span> <span class="o">=</span> <span class="n">config_file</span><span class="o">.</span><span class="n">read_bytes</span><span class="p">()</span> <span class="n">config_file</span><span class="o">.</span><span class="n">write_text</span><span class="p">(</span><span class="s1">'new content'</span><span class="p">,</span> <span class="n">encoding</span><span class="o">=</span><span class="s1">'utf-8'</span><span class="p">)</span> <span class="c1"># Glob patterns:</span> <span class="k">for</span> <span class="n">py_file</span> <span class="ow">in</span> <span class="n">data_dir</span><span class="o">.</span><span class="n">glob</span><span class="p">(</span><span class="s1">'**/*.py'</span><span class="p">):</span> <span class="nb">print</span><span class="p">(</span><span class="n">py_file</span><span class="o">.</span><span class="n">name</span><span class="p">)</span> <span class="c1"># Resolve absolute path:</span> <span class="n">absolute</span> <span class="o">=</span> <span class="n">config_file</span><span class="o">.</span><span class="n">resolve</span><span class="p">()</span> <span class="c1"># Resolves symlinks, makes absolute</span> <span class="c1"># In scripts: reliable __file__ reference</span> <span class="n">FIXTURES_DIR</span> <span class="o">=</span> <span class="n">Path</span><span class="p">(</span><span class="vm">__file__</span><span class="p">)</span><span class="o">.</span><span class="n">parent</span><span class="o">.</span><span class="n">resolve</span><span class="p">()</span> <span class="n">SAMPLE_FILE</span> <span class="o">=</span> <span class="n">FIXTURES_DIR</span> <span class="o">/</span> <span class="s1">'sample_traces.json'</span> </code></pre></div> <p>Key points: - Path(a) / 'b' / 'c' is cross-platform; os.path.join(a, 'b', 'c') is too verbose - Path(<strong>file</strong>).parent for the directory containing the current script - .resolve() makes path absolute and resolves symlinks - mkdir(parents=True, exist_ok=True) is equivalent to mkdir -p - Path objects work with open(), json.load(), and most stdlib functions</p>