Drop Duplicate Rows
<pre>
DataFrame customers
+-------------+--------+
| Column Name | Type   |
+-------------+--------+
| customer_id | int    |
| name        | object |
| email       | object |
+-------------+--------+
</pre>

<p>There are some duplicate rows in the DataFrame based on the <code>email</code> column.</p>

<p>Write a solution to remove these duplicate rows and keep only the <strong>first</strong> occurrence.</p>

<p>The result format is in the following example.</p>

<p>&nbsp;</p>
<pre>
<strong class="example">Example 1:</strong>
<strong>Input:</strong>
+-------------+---------+---------------------+
| customer_id | name    | email               |
+-------------+---------+---------------------+
| 1           | Ella    | emily@example.com   |
| 2           | David   | michael@example.com |
| 3           | Zachary | sarah@example.com   |
| 4           | Alice   | john@example.com    |
| 5           | Finn    | john@example.com    |
| 6           | Violet  | alice@example.com   |
+-------------+---------+---------------------+
<strong>Output: </strong> 
+-------------+---------+---------------------+
| customer_id | name    | email               |
+-------------+---------+---------------------+
| 1           | Ella    | emily@example.com   |
| 2           | David   | michael@example.com |
| 3           | Zachary | sarah@example.com   |
| 4           | Alice   | john@example.com    |
| 6           | Violet  | alice@example.com   |
+-------------+---------+---------------------+
<strong>Explanation:</strong>
Alic (customer_id = 4) and Finn (customer_id = 5) both use john@example.com, so only the first occurrence of this email is retained.
</pre>

[]
[]
[{"value": "pythondata", "text": "Pandas", "defaultCode": "import pandas as pd\n\ndef dropDuplicateEmails(customers: pd.DataFrame) -> pd.DataFrame:\n    "}]
{
  "pythondata": [
    "customers = pd.DataFrame([], columns=['customer_id', 'name', 'email']).astype({'customer_id':'Int64', 'name':'object', 'email':'object'})"
  ],
  "database": true,
  "name": "dropDuplicateEmails",
  "languages": [
    "pythondata"
  ]
}
{"pythondata": ["Pandas", "<p>Python 3.10 with Pandas 2.2.2 and NumPy 1.26.4</p>"]}
[]