Quick quesiton on getting a single historical value (for example).  Let's say I'm looking for the close of IBM at 2019-05-23 00:00:00.  If I use the following code to create the history for this - how can I call that single index via the DataFrame (this is in py) to get this value.  It may just be me not knowing much about DataFrames, but it seems like I can't call this via the index.

self.SetStartDate(2019, 5, 24)

date1 = datetime.datetime(2019, 5, 23,0,0,0)
self.AddEquity("IBM", Resolution.Minute)
df = self.History(self.Symbol("IBM"), 2880, Resolution.Minute)

#what I thought would work but does not:

Any help would be appreciated!  I'm sure I'm doing something silly here.