finding the position of an element within a numpy array in python : <p>I want to ask a question about finding the position of an element within an array in Python's numpy package. </p>

<p>I am using Jupyter Notebook for Python 3 and have the following code illustrated below:</p>

<pre><code>concentration_list = array([172.95, 173.97, 208.95])
</code></pre>

<p>and I want to write a block of code that would be able to return the position of an element within the array. </p>

<p>For this purpose, I wanted to use <code>172.95</code> to demonstrate. </p>

<p>Initially, I attempted to use <code>.index()</code>, passing in <code>172.95</code> inside the parentheses but this did not work as numpy does not recognise the <code>.index()</code> method -</p>

<pre><code>concentration_position = concentration_list.index(172.95)

AttributeError: 'numpy.ndarray' object has no attribute 'index'
</code></pre>

<p>The Sci.py documentation did not mention anything about such a method being available when I accessed the site. </p>

<p>Is there any function available (that I may not have discovered) to solve the problem?</p>
