snipt

Ctrl+h for KB shortcuts

Python

Retrieve Django objects grouped by first letter of an attribute

"""
ex:
  authors_by_letter = fetch_objects_by_letter(Author, 'name')

returns:
  {u'A': [<Author: Ayn Rand>], u'J': [<Author: Jessica Simpson>], u'L': [<Author: Lord Voldemort>], u'T': [<Author: Trey Parker>]}

"""
def fetch_objects_by_letter(model, attr):
	qs = model.objects.all().order_by(attr)
	
	objs_by_letter = dict()
	for obj in qs:
		try:
			tmp = objs_by_letter[obj.__dict__[attr][0]]
		except KeyError:
			objs_by_letter[obj.__dict__[attr][0]] = list()
			
		objs_by_letter[obj.__dict__[attr][0]].append(obj)
		
	return objs_by_letter
https://snipt.net/embed/7d675453ee749ced36c62eaefc02353a/
/raw/7d675453ee749ced36c62eaefc02353a/
7d675453ee749ced36c62eaefc02353a
python
Python
21
2019-06-17T11:14:01
True
False
False
/api/public/snipt/9643/
retrieve-django-objects-grouped-by-first-letter-of-an-attribute
<table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><a href="#L-1"> 1</a> <a href="#L-2"> 2</a> <a href="#L-3"> 3</a> <a href="#L-4"> 4</a> <a href="#L-5"> 5</a> <a href="#L-6"> 6</a> <a href="#L-7"> 7</a> <a href="#L-8"> 8</a> <a href="#L-9"> 9</a> <a href="#L-10">10</a> <a href="#L-11">11</a> <a href="#L-12">12</a> <a href="#L-13">13</a> <a href="#L-14">14</a> <a href="#L-15">15</a> <a href="#L-16">16</a> <a href="#L-17">17</a> <a href="#L-18">18</a> <a href="#L-19">19</a> <a href="#L-20">20</a> <a href="#L-21">21</a></pre></div></td><td class="code"><div class="highlight"><pre><span></span><span id="L-1"><a name="L-1"></a><span class="sd">&quot;&quot;&quot;</span> </span><span id="L-2"><a name="L-2"></a><span class="sd">ex:</span> </span><span id="L-3"><a name="L-3"></a><span class="sd"> authors_by_letter = fetch_objects_by_letter(Author, &#39;name&#39;)</span> </span><span id="L-4"><a name="L-4"></a> </span><span id="L-5"><a name="L-5"></a><span class="sd">returns:</span> </span><span id="L-6"><a name="L-6"></a><span class="sd"> {u&#39;A&#39;: [&lt;Author: Ayn Rand&gt;], u&#39;J&#39;: [&lt;Author: Jessica Simpson&gt;], u&#39;L&#39;: [&lt;Author: Lord Voldemort&gt;], u&#39;T&#39;: [&lt;Author: Trey Parker&gt;]}</span> </span><span id="L-7"><a name="L-7"></a> </span><span id="L-8"><a name="L-8"></a><span class="sd">&quot;&quot;&quot;</span> </span><span id="L-9"><a name="L-9"></a><span class="k">def</span> <span class="nf">fetch_objects_by_letter</span><span class="p">(</span><span class="n">model</span><span class="p">,</span> <span class="n">attr</span><span class="p">):</span> </span><span id="L-10"><a name="L-10"></a> <span class="n">qs</span> <span class="o">=</span> <span class="n">model</span><span class="o">.</span><span class="n">objects</span><span class="o">.</span><span class="n">all</span><span class="p">()</span><span class="o">.</span><span class="n">order_by</span><span class="p">(</span><span class="n">attr</span><span class="p">)</span> </span><span id="L-11"><a name="L-11"></a> </span><span id="L-12"><a name="L-12"></a> <span class="n">objs_by_letter</span> <span class="o">=</span> <span class="nb">dict</span><span class="p">()</span> </span><span id="L-13"><a name="L-13"></a> <span class="k">for</span> <span class="n">obj</span> <span class="ow">in</span> <span class="n">qs</span><span class="p">:</span> </span><span id="L-14"><a name="L-14"></a> <span class="k">try</span><span class="p">:</span> </span><span id="L-15"><a name="L-15"></a> <span class="n">tmp</span> <span class="o">=</span> <span class="n">objs_by_letter</span><span class="p">[</span><span class="n">obj</span><span class="o">.</span><span class="n">__dict__</span><span class="p">[</span><span class="n">attr</span><span class="p">][</span><span class="mi">0</span><span class="p">]]</span> </span><span id="L-16"><a name="L-16"></a> <span class="k">except</span> <span class="ne">KeyError</span><span class="p">:</span> </span><span id="L-17"><a name="L-17"></a> <span class="n">objs_by_letter</span><span class="p">[</span><span class="n">obj</span><span class="o">.</span><span class="n">__dict__</span><span class="p">[</span><span class="n">attr</span><span class="p">][</span><span class="mi">0</span><span class="p">]]</span> <span class="o">=</span> <span class="nb">list</span><span class="p">()</span> </span><span id="L-18"><a name="L-18"></a> </span><span id="L-19"><a name="L-19"></a> <span class="n">objs_by_letter</span><span class="p">[</span><span class="n">obj</span><span class="o">.</span><span class="n">__dict__</span><span class="p">[</span><span class="n">attr</span><span class="p">][</span><span class="mi">0</span><span class="p">]]</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">obj</span><span class="p">)</span> </span><span id="L-20"><a name="L-20"></a> </span><span id="L-21"><a name="L-21"></a> <span class="k">return</span> <span class="n">objs_by_letter</span> </span></pre></div> </td></tr></table>
django, query, sort