How to do conditional statements in pandas/python with null values
<p>How do I do condition replacements in pandas?</p>

<pre><code>df = pd.DataFrame([[1, 2, 3], [4, None, None], [None, None, 9]])
</code></pre>

<p>In R - think this code is very easy to understand:</p>

<pre><code>library(dplyr)
df = df %&gt;% 
mutate(   #   mutate means create new column for non-r people
my_new_column = ifelse( is.na(the_2nd_column)==TRUE &amp; is.na(the_3rd_column)==TRUE, ' abc', 'cuz')
</code></pre>

<p>how do I do this in pandas - probably dumb question with the syntax, but I have heard np.where is the equivalent of if else in R...</p>

<pre><code>df['new_column'] = np.where(np.nan(....help here with a conditional....))
</code></pre>