How to get row number in dataframe in Pandas? : <p>How can I get the number of the row in a dataframe that contains a certain value in a certain column using Pandas? For example, I have the following dataframe:</p>

<pre><code>     ClientID  LastName
0    34        Johnson
1    67        Smith
2    53        Brows  
</code></pre>

<p>How can I find the number of the row that has 'Smith' in 'LastName' column?</p>
