Pandas boolean comparisson on dataframe

Question

I am getting the error when I make a comparison on a single element in a dataframe, but I don\'t understand why.

I have a dataframe df with timeseries data for a nu

Answer 1

Problem is you need compare scalar for return scalar (True, False), but there is one item Series, which is converted to one item boolean Series.

Solutions is converting to scalar using Series.item or values with selecting first value by [0]:

customer_ID = '8143511'
ts = '2012-07-01 00:00:00'

print (df[[customer_ID]].loc[ts].item())
nan

if pd.isnull(df[[customer_ID]].loc[ts]).item():
    print ('super')

print (df[[customer_ID]].loc[ts].values[0])
nan

if pd.isnull(df[[customer_ID]].loc[ts]).values[0]:
    print ('super')

But if use DataFrame.loc, get scalar (if not duplicated index or columns names):

print (df.loc[ts, customer_ID])
nan

customer_ID = '8143511'
ts = '2012-07-01 00:00:00'
if pd.isnull(df.loc[ts, customer_ID]):
    print ('super')