From 036b94e66872049acdb2791a14192e5438bece6f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jure=20=C5=A0orn?= <sornjure@gmail.com>
Date: Tue, 13 May 2025 00:05:00 +0200
Subject: [PATCH] Inheritence to Subclass in Class, Paths, CSV
---
README.md | 32 +++++++++++++++++---------------
index.html | 35 ++++++++++++++++++++---------------
pdf/index_for_pdf.html | 2 +-
3 files changed, 38 insertions(+), 31 deletions(-)
diff --git a/README.md b/README.md
index c906e61..4f2da95 100644
--- a/README.md
+++ b/README.md
@@ -995,29 +995,31 @@ Z = make_dataclass('Z', ['a']); print/str/repr(Z(<obj>))
>>> <obj>
```
-### Inheritance
+### Subclass
+* **Inheritance is a mechanism that enables a class to extend another class (subclass to extend its parent), and by doing so inherit all its methods and attributes.**
+* **Subclass can then add its own methods and attributes or override inherited ones by reusing their names.**
+
```python
class Person:
def __init__(self, name):
self.name = name
+ def __repr__(self):
+ return f'Person({self.name!r})'
+ def __lt__(self, other):
+ return self.name < other.name
class Employee(Person):
def __init__(self, name, staff_num):
super().__init__(name)
self.staff_num = staff_num
+ def __repr__(self):
+ return f'Employee({self.name!r}, {self.staff_num})'
```
-#### Multiple inheritance:
-```python
-class A: pass
-class B: pass
-class C(A, B): pass
-```
-
-**MRO determines the order in which parent classes are traversed when searching for a method or an attribute:**
```python
->>> C.mro()
-[<class 'C'>, <class 'A'>, <class 'B'>, <class 'object'>]
+>>> people = {Person('Ann'), Employee('Bob', 0)}
+>>> sorted(people)
+[Person('Ann'), Employee('Bob', 0)]
```
### Type Annotations
@@ -1685,8 +1687,8 @@ from pathlib import Path
<Path> = <Path>.parent # Returns Path without the final component.
<str> = <Path>.name # Returns final component as a string.
<str> = <Path>.suffix # Returns name's last extension, e.g. '.py'.
-<str> = <Path>.stem # Returns name without last extension.
-<tup.> = <Path>.parts # Returns all path's components as strings.
+<str> = <Path>.stem # Returns name without the last extension.
+<tup.> = <Path>.parts # Returns all components as strings.
```
```python
@@ -1820,10 +1822,10 @@ import csv
<list> = next(<reader>) # Returns next row as a list of strings.
<list> = list(<reader>) # Returns a list of remaining rows.
```
-* **File must be opened with a `'newline=""'` argument, or newlines embedded inside quoted fields will not be interpreted correctly!**
+* **File must be opened with a `'newline=""'` argument, or all '\r\n' sequences inside quoted fields will get converted to '\n'!**
* **To print the spreadsheet to the console use [Tabulate](#table) library.**
* **For XML and binary Excel files (xlsx, xlsm and xlsb) use [Pandas](#dataframe-plot-encode-decode) library.**
-* **Reader accepts any iterator of strings, not just files.**
+* **Reader accepts any collection of strings, not just files.**
### Write
```python
diff --git a/index.html b/index.html
index d2af9dd..a26d191 100644
--- a/index.html
+++ b/index.html
@@ -56,7 +56,7 @@
<body>
<header>
- <aside>May 9, 2025</aside>
+ <aside>May 12, 2025</aside>
<a href="https://gto76.github.io" rel="author">Jure Šorn</a>
</header>
@@ -849,25 +849,30 @@ Z = make_dataclass(<span class="hljs-string">'Z'</span>, [<span class="hljs-stri
<span class="hljs-meta">>>> </span><obj>
</code></pre></div>
-<div><h3 id="inheritance">Inheritance</h3><pre><code class="python language-python hljs"><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Person</span>:</span>
+<div><h3 id="subclass">Subclass</h3><ul>
+<li><strong>Inheritance is a mechanism that enables a class to extend another class (subclass to extend its parent), and by doing so inherit all its methods and attributes.</strong></li>
+<li><strong>Subclass can then add its own methods and attributes or override inherited ones by reusing their names.</strong></li>
+</ul><pre><code class="python language-python hljs"><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Person</span>:</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__init__</span><span class="hljs-params">(self, name)</span>:</span>
self.name = name
+ <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__repr__</span><span class="hljs-params">(self)</span>:</span>
+ <span class="hljs-keyword">return</span> <span class="hljs-string">f'Person(<span class="hljs-subst">{self.name!r}</span>)'</span>
+ <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__lt__</span><span class="hljs-params">(self, other)</span>:</span>
+ <span class="hljs-keyword">return</span> self.name < other.name
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Employee</span><span class="hljs-params">(Person)</span>:</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__init__</span><span class="hljs-params">(self, name, staff_num)</span>:</span>
super().__init__(name)
self.staff_num = staff_num
+ <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__repr__</span><span class="hljs-params">(self)</span>:</span>
+ <span class="hljs-keyword">return</span> <span class="hljs-string">f'Employee(<span class="hljs-subst">{self.name!r}</span>, <span class="hljs-subst">{self.staff_num}</span>)'</span>
</code></pre></div>
-<div><h4 id="multipleinheritance">Multiple inheritance:</h4><pre><code class="python language-python hljs"><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">A</span>:</span> <span class="hljs-keyword">pass</span>
-<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">B</span>:</span> <span class="hljs-keyword">pass</span>
-<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">C</span><span class="hljs-params">(A, B)</span>:</span> <span class="hljs-keyword">pass</span>
-</code></pre></div>
-<p><strong>MRO determines the order in which parent classes are traversed when searching for a method or an attribute:</strong></p>
-<pre><code class="python language-python hljs"><span class="hljs-meta">>>> </span>C.mro()
-[<<span class="hljs-class"><span class="hljs-title">class</span> '<span class="hljs-title">C</span>'>, <<span class="hljs-title">class</span> '<span class="hljs-title">A</span>'>, <<span class="hljs-title">class</span> '<span class="hljs-title">B</span>'>, <<span class="hljs-title">class</span> '<span class="hljs-title">object</span>'>]
-</span></code></pre>
+<pre><code class="python language-python hljs"><span class="hljs-meta">>>> </span>people = {Person(<span class="hljs-string">'Ann'</span>), Employee(<span class="hljs-string">'Bob'</span>, <span class="hljs-number">0</span>)}
+<span class="hljs-meta">>>> </span>sorted(people)
+[Person(<span class="hljs-string">'Ann'</span>), Employee(<span class="hljs-string">'Bob'</span>, <span class="hljs-number">0</span>)]
+</code></pre>
<div><h3 id="typeannotations">Type Annotations</h3><ul>
<li><strong>They add type hints to variables, arguments and functions (<code class="python hljs"><span class="hljs-string">'def f() -> <type>:'</span></code>).</strong></li>
<li><strong>Hints are used by type checkers like <a href="https://pypi.org/project/mypy/">mypy</a>, data validation libraries such as <a href="https://pypi.org/project/pydantic/">Pydantic</a> and lately also by <a href="https://pypi.org/project/Cython/">Cython</a> compiler. However, they are not enforced by CPython interpreter.</strong></li>
@@ -1431,8 +1436,8 @@ args = p.parse_args() <span class="h
<pre><code class="python language-python hljs"><Path> = <Path>.parent <span class="hljs-comment"># Returns Path without the final component.</span>
<str> = <Path>.name <span class="hljs-comment"># Returns final component as a string.</span>
<str> = <Path>.suffix <span class="hljs-comment"># Returns name's last extension, e.g. '.py'.</span>
-<str> = <Path>.stem <span class="hljs-comment"># Returns name without last extension.</span>
-<tup.> = <Path>.parts <span class="hljs-comment"># Returns all path's components as strings.</span>
+<str> = <Path>.stem <span class="hljs-comment"># Returns name without the last extension.</span>
+<tup.> = <Path>.parts <span class="hljs-comment"># Returns all components as strings.</span>
</code></pre>
<pre><code class="python language-python hljs"><iter> = <Path>.iterdir() <span class="hljs-comment"># Returns directory contents as Path objects.</span>
<iter> = <Path>.glob(<span class="hljs-string">'<pattern>'</span>) <span class="hljs-comment"># Returns Paths matching the wildcard pattern.</span>
@@ -1522,10 +1527,10 @@ CompletedProcess(args=[<span class="hljs-string">'bc'</span>, <span class="hljs-
</code></pre></div>
<ul>
-<li><strong>File must be opened with a <code class="python hljs"><span class="hljs-string">'newline=""'</span></code> argument, or newlines embedded inside quoted fields will not be interpreted correctly!</strong></li>
+<li><strong>File must be opened with a <code class="python hljs"><span class="hljs-string">'newline=""'</span></code> argument, or all '\r\n' sequences inside quoted fields will get converted to '\n'!</strong></li>
<li><strong>To print the spreadsheet to the console use <a href="#table">Tabulate</a> library.</strong></li>
<li><strong>For XML and binary Excel files (xlsx, xlsm and xlsb) use <a href="#dataframeplotencodedecode">Pandas</a> library.</strong></li>
-<li><strong>Reader accepts any iterator of strings, not just files.</strong></li>
+<li><strong>Reader accepts any collection of strings, not just files.</strong></li>
</ul>
<div><h3 id="write">Write</h3><pre><code class="python language-python hljs"><writer> = csv.writer(<file>) <span class="hljs-comment"># Also: `dialect='excel', delimiter=','`.</span>
<writer>.writerow(<collection>) <span class="hljs-comment"># Encodes objects using `str(<el>)`.</span>
@@ -2940,7 +2945,7 @@ $ deactivate <span class="hljs-comment"># Deactivates the active
<footer>
- <aside>May 9, 2025</aside>
+ <aside>May 12, 2025</aside>
<a href="https://gto76.github.io" rel="author">Jure Šorn</a>
</footer>
diff --git a/pdf/index_for_pdf.html b/pdf/index_for_pdf.html
index 9cb299e..4327865 100644
--- a/pdf/index_for_pdf.html
+++ b/pdf/index_for_pdf.html
@@ -131,7 +131,7 @@
<strong>strings, <a href="#abstractbaseclasses">4</a>-<a href="#comparisonofpresentationtypes">7</a>, <a href="#class">14</a></strong><br>
<strong>struct module, <a href="#struct">28</a>-<a href="#integertypesuseacapitalletterforunsignedtypeminimumandstandardsizesareinbrackets">29</a></strong><br>
<strong>subprocess module, <a href="#sends11tothebasiccalculatorandcapturesitsoutput">25</a></strong><br>
-<strong>super function, <a href="#inheritance">14</a></strong><br>
+<strong>super function, <a href="#subclass">14</a></strong><br>
<strong>sys module, <a href="#cache">13</a>, <a href="#exit">21</a>-<a href="#commandlinearguments">22</a></strong> </p>
<h3 id="t">T</h3>
<p><strong>table, <a href="#csv">26</a>, <a href="#example-1">27</a>, <a href="#table">34</a>, <a href="#numpy">37</a>-<a href="#indexing">38</a>, <a href="#dataframe">45</a>-<a href="#dataframeaggregatetransformmap">46</a></strong><br>