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<h1 class="post-title">Pandas 05 - Eksik - Kayıp Veri Yöntemleri</h1>
<span class="post-date">Sal 12 Temmuz 2022</span>
<h1>Eksik / Kayıp Veri Tespiti ve Düzenleme Yöntemleri</h1>
<p>Veri çerçevemizde eksik veri (excel tablosundaki boş hücre gibi düşünebiliriz) olup olmadığını, varsa kaç adet olduğunu tespit edebileceğimiz Pandas yöntemleri mevcuttur. Bunları incelemeye başlayalım.</p>
<h3>isnull() Fonksiyonu</h3>
<p>Veri çerçevemizde eksik verileri <strong>isnull()</strong> fonksiyonu ile tespit edebiliriz. <strong>isnull</strong> ifadesini, <strong>boş mu?, geçersiz mi?, kayıp/eksik mi?</strong> sorusu olarak düşünebilirsiniz.
Hemen inceleyelim bakalım, acaba <strong>IMDB</strong> listemizde eksik veri var mı? varsa hangi sütunda ne kadar eksik veri var?</p>
<div class="highlight"><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="n">imdb</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">read_excel</span><span class="p">(</span><span class="s2">"Veri_Setleri/imdb.xlsx"</span><span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">imdb</span><span class="o">.</span><span class="n">isnull</span><span class="p">())</span>
</code></pre></div>
<table>
<thead>
<tr>
<th></th>
<th>Film_Adı</th>
<th>Yıl</th>
<th>Puan</th>
<th>Oylayan_Kişi</th>
</tr>
</thead>
<tbody>
<tr>
<td>0</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
<tr>
<td>1</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
<tr>
<td>2</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
<tr>
<td>3</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
<tr>
<td>4</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
<tr>
<td>...</td>
<td>...</td>
<td>...</td>
<td>...</td>
<td>...</td>
</tr>
<tr>
<td>242</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
<tr>
<td>243</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
<tr>
<td>244</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
<tr>
<td>245</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
<tr>
<td>246</td>
<td>False</td>
<td>False</td>
<td>False</td>
<td>False</td>
</tr>
</tbody>
</table>
<p>247 rows × 4 columns</p>
<p>Görüldüğü üzere, bu fonksiyon, veri çerçevesindeki her hücreye, kayıp/eksik veri olup olmadığı verisini yazıyor. <strong>False</strong> Yanlış, yani Eksik/Kayıp veri <strong>YOK</strong>, <strong>True</strong> ise Doğru yan, Eksik/Kayıp veri <strong>VAR</strong> anlamına gelir.
Tabloya tek tek bakmak yerine, tüm sütunlardaki eksik/kayıp verileri python'a saydırıp, sonucu görüntüleyebiliriz.
Python'da aşina olduğumuz <strong>sum()</strong> fonksiyonu işimize yarayacaktır.</p>
<div class="highlight"><pre><span></span><code><span class="nb">print</span><span class="p">(</span><span class="n">imdb</span><span class="o">.</span><span class="n">isnull</span><span class="p">()</span><span class="o">.</span><span class="n">sum</span><span class="p">())</span>
</code></pre></div>
<div class="highlight"><pre><span></span><code><span class="n">Film_Adı</span> <span class="mi">0</span>
<span class="n">Yıl</span> <span class="mi">0</span>
<span class="n">Puan</span> <span class="mi">0</span>
<span class="n">Oylayan_Kişi</span> <span class="mi">0</span>
<span class="n">dtype</span><span class="p">:</span> <span class="n">int64</span>
</code></pre></div>
<p>Gördüğümüz kadarıyla tüm sonuçlar sıfır, yani veri çerçevemizde hiç eksik/kayıp veri bulunmamaktadır.</p>
<p>İçerisinde Kayıp/Eksik veri olan bir <strong>Calc</strong> tablosunu, veri çerçevesine dönüştürerek inceleyelim.</p>
<div class="highlight"><pre><span></span><code><span class="n">veri</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">read_excel</span><span class="p">(</span><span class="s2">"Veri_Setleri/eksik_veri.ods"</span><span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">veri</span><span class="p">)</span>
</code></pre></div>
<table>
<thead>
<tr>
<th></th>
<th>Film_Adı</th>
<th>Yıl</th>
<th>Puan</th>
<th>Oylayan_Kişi</th>
</tr>
</thead>
<tbody>
<tr>
<td>0</td>
<td>The Shawshank Redemption</td>
<td>1994.0</td>
<td>9,2</td>
<td>1071904.0</td>
</tr>
<tr>
<td>1</td>
<td>The Godfather</td>
<td>1972.0</td>
<td>9,2</td>
<td>751381.0</td>
</tr>
<tr>
<td>2</td>
<td>The Godfather: Part II</td>
<td>1974.0</td>
<td>9</td>
<td>488889.0</td>
</tr>
<tr>
<td>3</td>
<td>Pulp Fiction</td>
<td>1994.0</td>
<td>8,9</td>
<td>830504.0</td>
</tr>
<tr>
<td>4</td>
<td>The Dark Knight</td>
<td>2008.0</td>
<td>8,9</td>
<td>1045186.0</td>
</tr>
<tr>
<td>5</td>
<td>12 Angry Men</td>
<td>1957.0</td>
<td>8,9</td>
<td>NaN</td>
</tr>
<tr>
<td>6</td>
<td>Schindler's List</td>
<td>1993.0</td>
<td>8,9</td>
<td>545703.0</td>
</tr>
<tr>
<td>7</td>
<td>The Lord of the Rings: The Return of the King</td>
<td>2003.0</td>
<td>8,8</td>
<td>758388.0</td>
</tr>
<tr>
<td>8</td>
<td>Fight Club</td>
<td>1999.0</td>
<td>8,8</td>
<td>814389.0</td>
</tr>
<tr>
<td>9</td>
<td>Star Wars: Episode V - The Empire Strikes Back</td>
<td>1980.0</td>
<td>8,8</td>
<td>519895.0</td>
</tr>
<tr>
<td>10</td>
<td>The Lord of the Rings: The Fellowship of the R...</td>
<td>2001.0</td>
<td>8,8</td>
<td>784999.0</td>
</tr>
<tr>
<td>11</td>
<td>One Flew Over the Cuckoo's Nest</td>
<td>1975.0</td>
<td>8,7</td>
<td>447005.0</td>
</tr>
<tr>
<td>12</td>
<td>Goodfellas</td>
<td>1990.0</td>
<td>8,7</td>
<td>465445.0</td>
</tr>
<tr>
<td>13</td>
<td>Seven Samurai</td>
<td>NaN</td>
<td>8,7</td>
<td>161969.0</td>
</tr>
<tr>
<td>14</td>
<td>Inception</td>
<td>2010.0</td>
<td>8,7</td>
<td>844938.0</td>
</tr>
<tr>
<td>15</td>
<td>Star Wars</td>
<td>1977.0</td>
<td>8,7</td>
<td>NaN</td>
</tr>
<tr>
<td>16</td>
<td>Forrest Gump</td>
<td>1994.0</td>
<td>8,7</td>
<td>711386.0</td>
</tr>
<tr>
<td>17</td>
<td>The Matrix</td>
<td>1999.0</td>
<td>8,7</td>
<td>770559.0</td>
</tr>
<tr>
<td>18</td>
<td>The Lord of the Rings: The Two Towers</td>
<td>2002.0</td>
<td>8,7</td>
<td>680983.0</td>
</tr>
</tbody>
</table>
<p><strong>isnull().sum()</strong> metodlarıyla, yeni veri çerçevemizdeki eksik verilerin bilgilerini görelim</p>
<div class="highlight"><pre><span></span><code><span class="nb">print</span><span class="p">(</span><span class="n">veri</span><span class="o">.</span><span class="n">isnull</span><span class="p">()</span><span class="o">.</span><span class="n">sum</span><span class="p">())</span>
</code></pre></div>
<div class="highlight"><pre><span></span><code><span class="n">Film_Adı</span> <span class="mi">0</span>
<span class="n">Yıl</span> <span class="mi">1</span>
<span class="n">Puan</span> <span class="mi">0</span>
<span class="n">Oylayan_Kişi</span> <span class="mi">2</span>
<span class="n">dtype</span><span class="p">:</span> <span class="n">int64</span>
</code></pre></div>
<p><strong>Yıl</strong> sütununda 1, <strong>Oylayan_Kişi</strong> sütununda 2 adet eksik veri olduğu görünüyor. Eksik veri olan satır ve sütunları silmeye / temizlemeye çalışalım.</p>
<h3>dropna() Fonksiyonu</h3>
<p>Veri çerçevelerinde istediğimiz satır ve sütunları <strong>drop()</strong> metodu yardımı ile nasıl silebildiğimizi <a href="pandas-06-veri-duzenleme-yontemleri.html">burada</a> anlatıyoruz.</p>
<p>Veri Çerçevelerinde eksik veri bulunan satır ve sütunları otomatik olarak silmek için <strong>dropna()</strong> metodunu kullanabiliriz. Metodun kullanım şekli aşağıdaki gibidir.</p>
<div class="highlight"><pre><span></span><code><span class="n">VeriÇerçevesi_Adı</span><span class="o">.</span><span class="n">dropna</span><span class="p">(</span><span class="n">axis</span> <span class="o">=</span> <span class="mi">0</span> <span class="n">ya</span> <span class="n">da</span> <span class="mi">1</span><span class="p">,</span> <span class="n">inplace</span> <span class="o">=</span> <span class="kc">True</span> <span class="n">ya</span> <span class="n">da</span> <span class="kc">False</span><span class="p">)</span>
</code></pre></div>
<h4>axis Parametresi</h4>
<p>Eksenleri tanımlayan parametredir. Sıfır (0) Satırları, Bir (1) Sütunları temsil eder. Varsayılan değer Sıfır(0) yani Satırlardır.</p>
<h4>inplace Parametresi</h4>
<p>Gerçekleştirilen silme işleminin veri çerçevesinde kalıcı ya da geçici olmasını ayarladığımız parametredir. <strong>inplace = True</strong> yazılırsa, yapılan işlem kalıcı hale gelecektir.</p>
<div class="highlight"><pre><span></span><code><span class="nb">print</span><span class="p">(</span><span class="n">veri</span><span class="o">.</span><span class="n">dropna</span><span class="p">())</span>
</code></pre></div>
<table>
<thead>
<tr>
<th></th>
<th>Film_Adı</th>
<th>Yıl</th>
<th>Puan</th>
<th>Oylayan_Kişi</th>
</tr>
</thead>
<tbody>
<tr>
<td>0</td>
<td>The Shawshank Redemption</td>
<td>1994.0</td>
<td>9,2</td>
<td>1071904.0</td>
</tr>
<tr>
<td>1</td>
<td>The Godfather</td>
<td>1972.0</td>
<td>9,2</td>
<td>751381.0</td>
</tr>
<tr>
<td>2</td>
<td>The Godfather: Part II</td>
<td>1974.0</td>
<td>9</td>
<td>488889.0</td>
</tr>
<tr>
<td>3</td>
<td>Pulp Fiction</td>
<td>1994.0</td>
<td>8,9</td>
<td>830504.0</td>
</tr>
<tr>
<td>4</td>
<td>The Dark Knight</td>
<td>2008.0</td>
<td>8,9</td>
<td>1045186.0</td>
</tr>
<tr>
<td>6</td>
<td>Schindler's List</td>
<td>1993.0</td>
<td>8,9</td>
<td>545703.0</td>
</tr>
<tr>
<td>7</td>
<td>The Lord of the Rings: The Return of the King</td>
<td>2003.0</td>
<td>8,8</td>
<td>758388.0</td>
</tr>
<tr>
<td>8</td>
<td>Fight Club</td>
<td>1999.0</td>
<td>8,8</td>
<td>814389.0</td>
</tr>
<tr>
<td>9</td>
<td>Star Wars: Episode V - The Empire Strikes Back</td>
<td>1980.0</td>
<td>8,8</td>
<td>519895.0</td>
</tr>
<tr>
<td>10</td>
<td>The Lord of the Rings: The Fellowship of the R...</td>
<td>2001.0</td>
<td>8,8</td>
<td>784999.0</td>
</tr>
<tr>
<td>11</td>
<td>One Flew Over the Cuckoo's Nest</td>
<td>1975.0</td>
<td>8,7</td>
<td>447005.0</td>
</tr>
<tr>
<td>12</td>
<td>Goodfellas</td>
<td>1990.0</td>
<td>8,7</td>
<td>465445.0</td>
</tr>
<tr>
<td>14</td>
<td>Inception</td>
<td>2010.0</td>
<td>8,7</td>
<td>844938.0</td>
</tr>
<tr>
<td>16</td>
<td>Forrest Gump</td>
<td>1994.0</td>
<td>8,7</td>
<td>711386.0</td>
</tr>
<tr>
<td>17</td>
<td>The Matrix</td>
<td>1999.0</td>
<td>8,7</td>
<td>770559.0</td>
</tr>
<tr>
<td>18</td>
<td>The Lord of the Rings: The Two Towers</td>
<td>2002.0</td>
<td>8,7</td>
<td>680983.0</td>
</tr>
</tbody>
</table>
<p><strong>dropna()</strong> metodunu parametresiz olarak kullandığımızda ( <em>veri.dropna()</em> ), sadece eksik veri tespit edilen <strong>satırlar</strong> silindi. Bir de eksik veri bulunan sütunları silmeye çalışalım.</p>
<div class="highlight"><pre><span></span><code><span class="nb">print</span><span class="p">(</span><span class="n">veri</span><span class="o">.</span><span class="n">dropna</span><span class="p">(</span><span class="n">axis</span> <span class="o">=</span> <span class="mi">1</span><span class="p">))</span>
</code></pre></div>
<table>
<thead>
<tr>
<th></th>
<th>Film_Adı</th>
<th>Puan</th>
</tr>
</thead>
<tbody>
<tr>
<td>0</td>
<td>The Shawshank Redemption</td>
<td>9,2</td>
</tr>
<tr>
<td>1</td>
<td>The Godfather</td>
<td>9,2</td>
</tr>
<tr>
<td>2</td>
<td>The Godfather: Part II</td>
<td>9</td>
</tr>
<tr>
<td>3</td>
<td>Pulp Fiction</td>
<td>8,9</td>
</tr>
<tr>
<td>4</td>
<td>The Dark Knight</td>
<td>8,9</td>
</tr>
<tr>
<td>5</td>
<td>12 Angry Men</td>
<td>8,9</td>
</tr>
<tr>
<td>6</td>
<td>Schindler's List</td>
<td>8,9</td>
</tr>
<tr>
<td>7</td>
<td>The Lord of the Rings: The Return of the King</td>
<td>8,8</td>
</tr>
<tr>
<td>8</td>
<td>Fight Club</td>
<td>8,8</td>
</tr>
<tr>
<td>9</td>
<td>Star Wars: Episode V - The Empire Strikes Back</td>
<td>8,8</td>
</tr>
<tr>
<td>10</td>
<td>The Lord of the Rings: The Fellowship of the R...</td>
<td>8,8</td>
</tr>
<tr>
<td>11</td>
<td>One Flew Over the Cuckoo's Nest</td>
<td>8,7</td>
</tr>
<tr>
<td>12</td>
<td>Goodfellas</td>
<td>8,7</td>
</tr>
<tr>
<td>13</td>
<td>Seven Samurai</td>
<td>8,7</td>
</tr>
<tr>
<td>14</td>
<td>Inception</td>
<td>8,7</td>
</tr>
<tr>
<td>15</td>
<td>Star Wars</td>
<td>8,7</td>
</tr>
<tr>
<td>16</td>
<td>Forrest Gump</td>
<td>8,7</td>
</tr>
<tr>
<td>17</td>
<td>The Matrix</td>
<td>8,7</td>
</tr>
<tr>
<td>18</td>
<td>The Lord of the Rings: The Two Towers</td>
<td>8,7</td>
</tr>
</tbody>
</table>
<h4>thresh Parametresi</h4>
<p><strong>dropna()</strong> Metodunun, <strong>thresh</strong> parametresi, veri çerçevesinde en az kaç adet veri varsa satır ya da sütunun silinmemesi gerektiğini belirtir. Bu parametreyi de hem satır hem de sütun için uygulayalım.</p>
<div class="highlight"><pre><span></span><code><span class="nb">print</span><span class="p">(</span><span class="n">veri</span><span class="o">.</span><span class="n">dropna</span><span class="p">(</span><span class="n">thresh</span><span class="o">=</span><span class="mi">3</span><span class="p">))</span>
</code></pre></div>
<table>
<thead>
<tr>
<th></th>
<th>Film_Adı</th>
<th>Yıl</th>
<th>Puan</th>
<th>Oylayan_Kişi</th>
</tr>
</thead>
<tbody>
<tr>
<td>0</td>
<td>The Shawshank Redemption</td>
<td>1994.0</td>
<td>9,2</td>
<td>1071904.0</td>
</tr>
<tr>
<td>1</td>
<td>The Godfather</td>
<td>1972.0</td>
<td>9,2</td>
<td>751381.0</td>
</tr>
<tr>
<td>2</td>
<td>The Godfather: Part II</td>
<td>1974.0</td>
<td>9</td>
<td>488889.0</td>
</tr>
<tr>
<td>3</td>
<td>Pulp Fiction</td>
<td>1994.0</td>
<td>8,9</td>
<td>830504.0</td>
</tr>
<tr>
<td>4</td>
<td>The Dark Knight</td>
<td>2008.0</td>
<td>8,9</td>
<td>1045186.0</td>
</tr>
<tr>
<td>5</td>
<td>12 Angry Men</td>
<td>1957.0</td>
<td>8,9</td>
<td>NaN</td>
</tr>
<tr>
<td>6</td>
<td>Schindler's List</td>
<td>1993.0</td>
<td>8,9</td>
<td>545703.0</td>
</tr>
<tr>
<td>7</td>
<td>The Lord of the Rings: The Return of the King</td>
<td>2003.0</td>
<td>8,8</td>
<td>758388.0</td>
</tr>
<tr>
<td>8</td>
<td>Fight Club</td>
<td>1999.0</td>
<td>8,8</td>
<td>814389.0</td>
</tr>
<tr>
<td>9</td>
<td>Star Wars: Episode V - The Empire Strikes Back</td>
<td>1980.0</td>
<td>8,8</td>
<td>519895.0</td>
</tr>
<tr>
<td>10</td>
<td>The Lord of the Rings: The Fellowship of the R...</td>
<td>2001.0</td>
<td>8,8</td>
<td>784999.0</td>
</tr>
<tr>
<td>11</td>
<td>One Flew Over the Cuckoo's Nest</td>
<td>1975.0</td>
<td>8,7</td>
<td>447005.0</td>
</tr>
<tr>
<td>12</td>
<td>Goodfellas</td>
<td>1990.0</td>
<td>8,7</td>
<td>465445.0</td>
</tr>
<tr>
<td>13</td>
<td>Seven Samurai</td>
<td>NaN</td>
<td>8,7</td>
<td>161969.0</td>
</tr>
<tr>
<td>14</td>
<td>Inception</td>
<td>2010.0</td>
<td>8,7</td>
<td>844938.0</td>
</tr>
<tr>
<td>15</td>
<td>Star Wars</td>
<td>1977.0</td>
<td>8,7</td>
<td>NaN</td>
</tr>
<tr>
<td>16</td>
<td>Forrest Gump</td>
<td>1994.0</td>
<td>8,7</td>
<td>711386.0</td>
</tr>
<tr>
<td>17</td>
<td>The Matrix</td>
<td>1999.0</td>
<td>8,7</td>
<td>770559.0</td>
</tr>
<tr>
<td>18</td>
<td>The Lord of the Rings: The Two Towers</td>
<td>2002.0</td>
<td>8,7</td>
<td>680983.0</td>
</tr>
</tbody>
</table>
<p><strong>veri.dropna(thresh=3)</strong>: Bu kod,en az 3 sağlam veri barındıran <strong>satırları</strong> silme demek oluyor. Aynı işlemi, <strong>axis</strong> parametresi kullanarak uygulamak istesek kodu şu şekilde yazmamız gerekecekti: <strong><em>veri.dropna(axis=0, thresh=3)</em></strong></p>
<p>Bir de en az 4 sağlam veri isteyelim bakalım ne sonuç alacağız. Veri çerçevemizde 4 adet sütun bulunduğu için, tümü geçerli, sağlam veri bulunan (dolu) sütunları bulmak istediğimiz anlamına geliyor.</p>
<div class="highlight"><pre><span></span><code><span class="nb">print</span><span class="p">(</span><span class="n">veri</span><span class="o">.</span><span class="n">dropna</span><span class="p">(</span><span class="n">thresh</span><span class="o">=</span><span class="mi">4</span><span class="p">))</span>
</code></pre></div>
<table>
<thead>
<tr>
<th></th>
<th>Film_Adı</th>
<th>Yıl</th>
<th>Puan</th>
<th>Oylayan_Kişi</th>
</tr>
</thead>
<tbody>
<tr>
<td>0</td>
<td>The Shawshank Redemption</td>
<td>1994.0</td>
<td>9,2</td>
<td>1071904.0</td>
</tr>
<tr>
<td>1</td>
<td>The Godfather</td>
<td>1972.0</td>
<td>9,2</td>
<td>751381.0</td>
</tr>
<tr>
<td>2</td>
<td>The Godfather: Part II</td>
<td>1974.0</td>
<td>9</td>
<td>488889.0</td>
</tr>
<tr>
<td>3</td>
<td>Pulp Fiction</td>
<td>1994.0</td>
<td>8,9</td>
<td>830504.0</td>
</tr>
<tr>
<td>4</td>
<td>The Dark Knight</td>
<td>2008.0</td>
<td>8,9</td>
<td>1045186.0</td>
</tr>
<tr>
<td>6</td>
<td>Schindler's List</td>
<td>1993.0</td>
<td>8,9</td>
<td>545703.0</td>
</tr>
<tr>
<td>7</td>
<td>The Lord of the Rings: The Return of the King</td>
<td>2003.0</td>
<td>8,8</td>
<td>758388.0</td>
</tr>
<tr>
<td>8</td>
<td>Fight Club</td>
<td>1999.0</td>
<td>8,8</td>
<td>814389.0</td>
</tr>
<tr>
<td>9</td>
<td>Star Wars: Episode V - The Empire Strikes Back</td>
<td>1980.0</td>
<td>8,8</td>
<td>519895.0</td>
</tr>
<tr>
<td>10</td>
<td>The Lord of the Rings: The Fellowship of the R...</td>
<td>2001.0</td>
<td>8,8</td>
<td>784999.0</td>
</tr>
<tr>
<td>11</td>
<td>One Flew Over the Cuckoo's Nest</td>
<td>1975.0</td>
<td>8,7</td>
<td>447005.0</td>
</tr>
<tr>
<td>12</td>
<td>Goodfellas</td>
<td>1990.0</td>
<td>8,7</td>
<td>465445.0</td>
</tr>
<tr>
<td>14</td>
<td>Inception</td>
<td>2010.0</td>
<td>8,7</td>
<td>844938.0</td>
</tr>
<tr>
<td>16</td>
<td>Forrest Gump</td>
<td>1994.0</td>
<td>8,7</td>
<td>711386.0</td>
</tr>
<tr>
<td>17</td>
<td>The Matrix</td>
<td>1999.0</td>
<td>8,7</td>
<td>770559.0</td>
</tr>
<tr>
<td>18</td>
<td>The Lord of the Rings: The Two Towers</td>
<td>2002.0</td>
<td>8,7</td>
<td>680983.0</td>
</tr>
</tbody>
</table>
<p>Tahmin ettiğiniz gibi, her satırda 4 bilgi bulunan satırlar kaldı, geri kalan <strong>satırlar</strong> silindi.</p>
<p>Bu metodu bir de <strong>sütunlarda</strong> uygulayalım. Veri çerçevemizde 19 satır veri bulunmaktadır. En az 18 adet veri bulunan (yani sütünlarda en fazla 1 adet eksik veriye izin verdiğimiz durumdaki) sütunlar kalsın, geri kalanlar silinsin istersek;</p>
<div class="highlight"><pre><span></span><code><span class="nb">print</span><span class="p">(</span><span class="n">veri</span><span class="o">.</span><span class="n">dropna</span><span class="p">(</span><span class="n">axis</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">thresh</span><span class="o">=</span><span class="mi">18</span><span class="p">))</span>
</code></pre></div>
<table>
<thead>
<tr>
<th></th>
<th>Film_Adı</th>
<th>Yıl</th>
<th>Puan</th>
</tr>
</thead>
<tbody>
<tr>
<td>0</td>
<td>The Shawshank Redemption</td>
<td>1994.0</td>
<td>9,2</td>
</tr>
<tr>
<td>1</td>
<td>The Godfather</td>
<td>1972.0</td>
<td>9,2</td>
</tr>
<tr>
<td>2</td>
<td>The Godfather: Part II</td>
<td>1974.0</td>
<td>9</td>
</tr>
<tr>
<td>3</td>
<td>Pulp Fiction</td>
<td>1994.0</td>
<td>8,9</td>
</tr>
<tr>
<td>4</td>
<td>The Dark Knight</td>
<td>2008.0</td>
<td>8,9</td>
</tr>
<tr>
<td>5</td>
<td>12 Angry Men</td>
<td>1957.0</td>
<td>8,9</td>
</tr>
<tr>
<td>6</td>
<td>Schindler's List</td>
<td>1993.0</td>
<td>8,9</td>
</tr>
<tr>
<td>7</td>
<td>The Lord of the Rings: The Return of the King</td>
<td>2003.0</td>
<td>8,8</td>
</tr>
<tr>
<td>8</td>
<td>Fight Club</td>
<td>1999.0</td>
<td>8,8</td>
</tr>
<tr>
<td>9</td>
<td>Star Wars: Episode V - The Empire Strikes Back</td>
<td>1980.0</td>
<td>8,8</td>
</tr>
<tr>
<td>10</td>
<td>The Lord of the Rings: The Fellowship of the R...</td>
<td>2001.0</td>
<td>8,8</td>
</tr>
<tr>
<td>11</td>
<td>One Flew Over the Cuckoo's Nest</td>
<td>1975.0</td>
<td>8,7</td>
</tr>
<tr>
<td>12</td>
<td>Goodfellas</td>
<td>1990.0</td>
<td>8,7</td>
</tr>
<tr>
<td>13</td>
<td>Seven Samurai</td>
<td>NaN</td>
<td>8,7</td>
</tr>
<tr>
<td>14</td>
<td>Inception</td>
<td>2010.0</td>
<td>8,7</td>
</tr>
<tr>
<td>15</td>
<td>Star Wars</td>
<td>1977.0</td>
<td>8,7</td>
</tr>
<tr>
<td>16</td>
<td>Forrest Gump</td>