Dickey-Fuller test in Python
<p>I was trying to figure out exactly what the following expression means:</p>
<h1>Perform Dickey-Fuller test:</h1>
<pre><code>print 'Results of Dickey-Fuller Test:'
dftest = adfuller(timeseries, autolag='AIC')
dfoutput = pd.Series(dftest[0:4], index=['Test Statistic','p-value','#Lags Used','Number of Observations Used'])
for key,value in dftest[4].items():
    dfoutput['Critical Value (%s)'%key] = value
print dfoutput
</code></pre>
<p>More specifically what does this [0:4] represent?</p>