deploy: d02155a

Author: yanglbme

en/lc/1565/index.html

@@ -40191,9 +40191,9 @@
       <ul class="md-nav__list">
 
           <li class="md-nav__item">
-  <a href="#solution-1" class="md-nav__link">
+  <a href="#solution-1-conditional-filtering-grouping-statistics" class="md-nav__link">
     <span class="md-ellipsis">
-      Solution 1
+      Solution 1: Conditional Filtering + Grouping Statistics
     </span>
   </a>
 
@@ -81407,7 +81407,7 @@ <h2 id="description">Description</h2>
 <p><strong class="example">Example 1:</strong></p>
 
 <pre>
-<strong>Input:</strong> 
+<strong>Input:</strong>
 Orders table:
 +----------+------------+-------------+------------+
 | order_id | order_date | customer_id | invoice    |
@@ -81423,7 +81423,7 @@ <h2 id="description">Description</h2>
 | 9        | 2021-01-07 | 3           | 31         |
 | 10       | 2021-01-15 | 2           | 20         |
 +----------+------------+-------------+------------+
-<strong>Output:</strong> 
+<strong>Output:</strong>
 +---------+-------------+----------------+
 | month   | order_count | customer_count |
 +---------+-------------+----------------+
@@ -81432,7 +81432,7 @@ <h2 id="description">Description</h2>
 | 2020-12 | 2           | 1              |
 | 2021-01 | 1           | 1              |
 +---------+-------------+----------------+
-<strong>Explanation:</strong> 
+<strong>Explanation:</strong>
 In September 2020 we have two orders from 2 different customers with invoices &gt; $20.
 In October 2020 we have two orders from 1 customer, and only one of the two orders has invoice &gt; $20.
 In November 2020 we have two orders from 2 different customers but invoices &lt; $20, so we don&#39;t include that month.
@@ -81445,8 +81445,9 @@ <h2 id="description">Description</h2>
 <h2 id="solutions">Solutions</h2>
 <!-- solution:start -->
 
-<h3 id="solution-1">Solution 1</h3>
-<div class="tabbed-set tabbed-alternate" data-tabs="1:1"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">MySQL</label></div>
+<h3 id="solution-1-conditional-filtering-grouping-statistics">Solution 1: Conditional Filtering + Grouping Statistics</h3>
+<p>We can first filter out orders with an amount greater than $20$, and then group by month to count the number of orders and customers.</p>
+<div class="tabbed-set tabbed-alternate" data-tabs="1:2"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">MySQL</label><label for="__tabbed_1_2">Python3</label></div>
 <div class="tabbed-content">
 <div class="tabbed-block">
 <div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span></span><span class="normal">1</span>
@@ -81463,7 +81464,41 @@ <h3 id="solution-1">Solution 1</h3>
 <span class="w">    </span><span class="k">COUNT</span><span class="p">(</span><span class="k">DISTINCT</span><span class="w"> </span><span class="n">customer_id</span><span class="p">)</span><span class="w"> </span><span class="k">AS</span><span class="w"> </span><span class="n">customer_count</span>
 <span class="k">FROM</span><span class="w"> </span><span class="n">Orders</span>
 <span class="k">WHERE</span><span class="w"> </span><span class="n">invoice</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="mi">20</span>
-<span class="k">GROUP</span><span class="w"> </span><span class="k">BY</span><span class="w"> </span><span class="k">month</span><span class="p">;</span>
+<span class="k">GROUP</span><span class="w"> </span><span class="k">BY</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
+</code></pre></div></td></tr></table></div>
+</div>
+<div class="tabbed-block">
+<div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span></span><span class="normal"> 1</span>
+<span class="normal"> 2</span>
+<span class="normal"> 3</span>
+<span class="normal"> 4</span>
+<span class="normal"> 5</span>
+<span class="normal"> 6</span>
+<span class="normal"> 7</span>
+<span class="normal"> 8</span>
+<span class="normal"> 9</span>
+<span class="normal">10</span>
+<span class="normal">11</span>
+<span class="normal">12</span>
+<span class="normal">13</span>
+<span class="normal">14</span>
+<span class="normal">15</span>
+<span class="normal">16</span></pre></div></td><td class="code"><div><pre><span></span><code><span class="kn">import</span> <span class="nn">pandas</span> <span class="k">as</span> <span class="nn">pd</span>
+
+
+<span class="k">def</span> <span class="nf">unique_orders_and_customers</span><span class="p">(</span><span class="n">orders</span><span class="p">:</span> <span class="n">pd</span><span class="o">.</span><span class="n">DataFrame</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="n">pd</span><span class="o">.</span><span class="n">DataFrame</span><span class="p">:</span>
+    <span class="n">filtered_orders</span> <span class="o">=</span> <span class="n">orders</span><span class="p">[</span><span class="n">orders</span><span class="p">[</span><span class="s2">&quot;invoice&quot;</span><span class="p">]</span> <span class="o">&gt;</span> <span class="mi">20</span><span class="p">]</span>
+    <span class="n">filtered_orders</span><span class="p">[</span><span class="s2">&quot;month&quot;</span><span class="p">]</span> <span class="o">=</span> <span class="p">(</span>
+        <span class="n">filtered_orders</span><span class="p">[</span><span class="s2">&quot;order_date&quot;</span><span class="p">]</span><span class="o">.</span><span class="n">dt</span><span class="o">.</span><span class="n">to_period</span><span class="p">(</span><span class="s2">&quot;M&quot;</span><span class="p">)</span><span class="o">.</span><span class="n">astype</span><span class="p">(</span><span class="nb">str</span><span class="p">)</span>
+    <span class="p">)</span>
+    <span class="n">result</span> <span class="o">=</span> <span class="p">(</span>
+        <span class="n">filtered_orders</span><span class="o">.</span><span class="n">groupby</span><span class="p">(</span><span class="s2">&quot;month&quot;</span><span class="p">)</span>
+        <span class="o">.</span><span class="n">agg</span><span class="p">(</span>
+            <span class="n">order_count</span><span class="o">=</span><span class="p">(</span><span class="s2">&quot;order_id&quot;</span><span class="p">,</span> <span class="s2">&quot;count&quot;</span><span class="p">),</span> <span class="n">customer_count</span><span class="o">=</span><span class="p">(</span><span class="s2">&quot;customer_id&quot;</span><span class="p">,</span> <span class="s2">&quot;nunique&quot;</span><span class="p">)</span>
+        <span class="p">)</span>
+        <span class="o">.</span><span class="n">reset_index</span><span class="p">()</span>
+    <span class="p">)</span>
+    <span class="k">return</span> <span class="n">result</span>
 </code></pre></div></td></tr></table></div>
 </div>
 </div>