how to initialize multiple columns to existing pandas DataFrame
<p>how can I initialize multiple columns in a single instance in an existing pandas DataFrame object? I can initialize single column at an instance, this way:</p>

<pre><code>df = pd.DataFrame({'a':[1,2,3],'b':[4,5,6]}, dtype='int')
df['c'] = 0
</code></pre>

<p>but i cannot do something like:</p>

<pre><code>df[['c','d']] = 0 or
df[['c']['d']] = 0
</code></pre>

<p>is there a way i can achieve this?</p>