How to convert "dd.mm.yyyy" into "yyyy-mm-dd" with Pandas in Python?
<p>I am reading a CSV file with intraday stock market data into a Pandas data frame. </p>

<pre><code>import pandas as pd

df = pd.read_csf('file.csv')
df.columns = ['Day', 'Time', 'Open', 'High', 'Low', 'Volume']
df.head()

    Day         Time    Open    High    Low     Close   Volume
0   23.11.2009  17:15   1104.00 1104.00 1104.00 1104.00 2
1   23.11.2009  17:20   1103.00 1103.00 1103.00 1103.00 11
2   23.11.2009  17:25   1103.75 1103.75 1103.75 1103.75 1
3   23.11.2009  17:30   1103.25 1103.25 1102.50 1102.50 3
4   23.11.2009  17:35   1103.25 1103.50 1103.00 1103.00 13
</code></pre>

<p>Unfortunately the date format in the column "Day" is in European date format: "dd.mm.yyyy". For example "28.11.2016".</p>

<p>How can I easily convert the "Day" column into something like "yyyy-mm-dd" or "2016-11-28"?</p>