Tuple no attribute error

[j.crater]

enumerate() returns a tuple containing two items. First is an index (starting with 0) and second is an item from the iterable you enumerated.

for line in enumerate(yrs_file):

Here line is a tuple (index, item), so you can't use split on it, which is a method of string type.
You could instead unpack the tuple into two variables like this:

for index, line in enumerate(yrs_file):

Then line will be a string which you can split.
You could also access only the second element of the tuple - the string you want to split:

for line in enumerate(yrs_file):
    (pdate,catg,amt,howp) = line[1].split(',')

But in any case, I don't really see why you would need enumerate() in your code at all.