Anyone knows why my code will only find the files for the first item in the list and not others? i.e-CodePudding

l='1001'

dts_lst=list(pd.date_range(datetime.strptime('2022-03-15', '%Y-%m-%d'), Dt_now, freq='D').strftime('%Y-%m-%d')) # list of days

p1=map(lambda x, y:Path(drive / x / 'foldera' / y / 'folderb' ), dts_lst, repeat(l))

to_search=['*a.LOG.bz2', '*b.LOG.bz2', '*c.LOG.bz2' ]

for i in to_search:
    f1=map(lambda x, y:Path(x).rglob(y), p2, repeat(i))
    for i2 in f1:
        print(f"this:::{i2}")

CodePudding user response：

Assuming that p2 is supposed to be p1, or is otherwise a map object similar to p1, then I see your problem. It starts with this line:

p1=map(lambda x, y:Path(drive / x / 'foldera' / y / 'folderb' ), dts_lst, repeat(l))

This creates a map object, which is a kind of iterator. Once you've built one of these, you access it like any other iterator, and it gives you a series of values until it reaches the end of whatever sequence it is meant to provide.

Your problem is that you are iterating over this map object three times. You can't do that. The first time you use the iterator, you exhaust it of values. After the first time, the iterator is effectively at the end of its sequence, and so continuing to query it for values will result in no values being returned.

The simplest way to fix your code is to create a list from the map object that you are assigning to p1:

p1=list(map(lambda x, y:Path(drive / x / 'foldera' / y / 'folderb' ), dts_lst, repeat(l)))

You can iterate over a list multiple times, so this works fine. Another option would be to put the calculation of p1 inside your loop so that you build a new map object each time through your loop:

l='1001'

dts_lst=list(pd.date_range(datetime.strptime('2022-03-15', '%Y-%m-%d'), Dt_now, freq='D').strftime('%Y-%m-%d')) # list of days
    
to_search=['*a.LOG.bz2', '*b.LOG.bz2', '*c.LOG.bz2' ]

for i in to_search:
    p1=map(lambda x, y:Path(drive / x / 'foldera' / y / 'folderb' ), dts_lst, repeat(l))
    p2 = p1  # ????
    f1=map(lambda x, y:Path(x).rglob(y), p2, repeat(i))
    for i2 in f1:
        print(f"this:::{i2}")

An aside...You don't need the repeat() iterators here. You can just let your lambda functions take a single parameter, and then refer directly to the value you were passing to repeat():

p1=map(lambda x:Path(drive / x / 'foldera' / l / 'folderb' ), dts_lst)

f1=map(lambda x:Path(x).rglob(i), p2)