How to lower all the elements in a pandas dataframe?
<p>Just a quick question guys, I have a pandas dataframe:</p>

<pre><code>In [11]: df = pd.DataFrame([['A', 'B'], ['C', E], ['D', 'C']],columns=['X', 'Y', 'Z'])

In [12]: df

Out[12]: 

   X  Y  Z
0  A  B  D
1  C  E  C
</code></pre>

<p>How can I convert to lower all the elements of <code>df</code>:</p>

<pre><code>Out[12]: 

   X  Y  Z
0  a  b  d
1  c  e  c
</code></pre>

<p>I look over the <a href="http://pandas.pydata.org/pandas-docs/stable/text.html" rel="noreferrer">documentation</a> and I tried the following:</p>

<pre><code>df = [[col.lower() for col in [df["X"],df["Y"], df["Z"]]]]
df
</code></pre>

<p>Nevertheless, it doesnt work. How to lower all the elements inside a pandas dataframe?.</p>