Get index when looping through one column of pandas
<p>I have a simple dataframe:</p>

<p>index, a, y
0    , 1, 2
1    , 4, 6
2    , 5, 8</p>

<p>I want to loop through the "a" column, and print out its index for a specific value.</p>

<pre><code>for x in df.a:
    if x == 4:
        print ("Index of that row")
</code></pre>

<p>What syntax should I use to obtain the index value when the for loop hits the specific value in the "a" column that I am seeking?</p>

<p>Thank You</p>