Efficiently check if value is present in any of given ranges

Question

I have two pandas DataFrame objects:

• A contains \'start\' and \'finish\' columns

• B has c

Answer 1

IIUC you want the output to be True if there is at least one interval in which the date is?

Is an apply(lambda) efficient enough for you? (It might be a little long for a big dataframe as it iterates over the rows of B). If it is, you can try this:

def in_range(date,start,finish):
    return (True in ((start < date) & (date < finish)).unique())

B.date.apply(lambda x: in_range(x,A.start,A.finish))

Output:

0     True
1    False
2     True
3    False
4    False

EDIT: MaxU's answer works better in fact. Here are the timers for 10 000 rows dataframes (A and B):

%timeit B2.date.apply(lambda x: in_range(x,A2.start,A2.finish))
1 loop, best of 3: 9.82 s per loop

%timeit B2.date.apply(lambda x: ((x >= A2.start) & (x <= A2.finish)).any())
1 loop, best of 3: 7.31 s per loop