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Dataclass, sortable
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‎README.md

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@@ -871,6 +871,20 @@ class C(A, B): pass
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[<class 'C'>, <class 'A'>, <class 'B'>, <class 'object'>]
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```
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### Dataclass
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**Decorator that automatically generates init(), repr() and eq() magic methods. Object can also be made sortable with `'order=True'` and/or immutable with `'frozen=True'`.**
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```python
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from dataclasses import dataclass, field
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@dataclass(order=False, frozen=False)
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class <class_name>:
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<attr_name_1>: <type>
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<attr_name_2>: <type> = <default_value>
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<attr_name_3>: list/dict/set = field(default_factory=list/dict/set)
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```
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* **Function field() is needed because `'<attr_name>: list = []'` would make a list that is shared among all instances.**
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* **Default_factory can be any callable.**
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### Copy
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```python
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from copy import copy, deepcopy
@@ -918,6 +932,25 @@ class MyHashable:
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return hash(self.a)
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```
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### Sortable
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* **With 'total_ordering' decorator you only need to provide one of lt(), gt(), le(), ge() magic methods.**
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```python
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from functools import total_ordering
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@total_ordering
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class MySortable:
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def __init__(self, a):
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self.a = a
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def __eq__(self, other):
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if isinstance(other, type(self)):
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return self.a == other.a
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return NotImplemented
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def __lt__(self, other):
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if isinstance(other, type(self)):
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return self.a < other.a
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return NotImplemented
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```
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### Collection
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* **Methods do not depend on each other, so they can be skipped if not needed.**
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* **Any object with defined getitem() is considered iterable, even if it lacks iter().**

‎index.html

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@@ -776,6 +776,20 @@ <h3 id="multipleinheritance">Multiple Inheritance</h3>
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<pre><code class="python language-python hljs"><span class="hljs-meta">&gt;&gt;&gt; </span>C.mro()
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[&lt;<span class="hljs-class"><span class="hljs-title">class</span> '<span class="hljs-title">C</span>'&gt;, &lt;<span class="hljs-title">class</span> '<span class="hljs-title">A</span>'&gt;, &lt;<span class="hljs-title">class</span> '<span class="hljs-title">B</span>'&gt;, &lt;<span class="hljs-title">class</span> '<span class="hljs-title">object</span>'&gt;]
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</span></code></pre>
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<h3 id="dataclass">Dataclass</h3>
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<p><strong>Decorator that automatically generates init(), repr() and eq() magic methods. Object can also be made sortable with <code class="python hljs"><span class="hljs-string">'order=True'</span></code> and/or immutable with <code class="python hljs"><span class="hljs-string">'frozen=True'</span></code>.</strong></p>
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<pre><code class="python language-python hljs"><span class="hljs-keyword">from</span> dataclasses <span class="hljs-keyword">import</span> dataclass, field
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<span class="hljs-meta">@dataclass(order=False, frozen=False)</span>
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<span class="hljs-class"><span class="hljs-keyword">class</span> &lt;<span class="hljs-title">class_name</span>&gt;:</span>
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&lt;attr_name_1&gt;: &lt;type&gt;
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&lt;attr_name_2&gt;: &lt;type&gt; = &lt;default_value&gt;
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&lt;attr_name_3&gt;: list/dict/set = field(default_factory=list/dict/set)
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</code></pre>
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<ul>
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<li><strong>Function field() is needed because <code class="python hljs"><span class="hljs-string">'&lt;attr_name&gt;: list = []'</span></code> would make a list that is shared among all instances.</strong></li>
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<li><strong>Default_factory can be any callable.</strong></li>
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</ul>
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<h3 id="copy">Copy</h3>
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<pre><code class="python language-python hljs"><span class="hljs-keyword">from</span> copy <span class="hljs-keyword">import</span> copy, deepcopy
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&lt;object&gt; = copy(&lt;object&gt;)
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<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__hash__</span><span class="hljs-params">(self)</span>:</span>
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<span class="hljs-keyword">return</span> hash(self.a)
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</code></pre>
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<h3 id="sortable">Sortable</h3>
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<ul>
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<li><strong>With 'total_ordering' decorator you only need to provide one of lt(), gt(), le(), ge() magic methods.</strong></li>
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</ul>
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<pre><code class="python language-python hljs"><span class="hljs-keyword">from</span> functools <span class="hljs-keyword">import</span> total_ordering
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<span class="hljs-meta">@total_ordering</span>
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<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MySortable</span>:</span>
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<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__init__</span><span class="hljs-params">(self, a)</span>:</span>
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self.a = a
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<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__eq__</span><span class="hljs-params">(self, other)</span>:</span>
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<span class="hljs-keyword">if</span> isinstance(other, type(self)):
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<span class="hljs-keyword">return</span> self.a == other.a
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<span class="hljs-keyword">return</span> <span class="hljs-built_in">NotImplemented</span>
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<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__lt__</span><span class="hljs-params">(self, other)</span>:</span>
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<span class="hljs-keyword">if</span> isinstance(other, type(self)):
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<span class="hljs-keyword">return</span> self.a &lt; other.a
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<span class="hljs-keyword">return</span> <span class="hljs-built_in">NotImplemented</span>
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</code></pre>
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<h3 id="collection">Collection</h3>
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<ul>
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<li><strong>Methods do not depend on each other, so they can be skipped if not needed.</strong></li>

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