I have a
table = [7, 5, [3, 6, [2]], 7, [1, [2, 3, [4]], 9, 2], 4]
Using recursion and the isinstance
function I need to sum all integers in table
. I can do it creating new list, extending it by lists from table. Then I got a normal list (no list in lists) and I can sum it.
But in this example I have no idea how to do it in a recursive way using that function. I understand how isinstance
works, but I have no idea how to use it in this example.
In code below I don't even get different value than True.
tab = [7, 5, [3, 6, [2]], 7, [1, [2, 3, [4]], 9, 2], 4]
for i in range(len(tab)):
print(isinstance(i, int))
Excepted output is sum of all numbers
Recursion means you have to use a function.
tab = [7, 5, [3, 6, [2]], 7, [1, [2, 3, [4]], 9, 2], 4]
def int_sum(tbl):
s = 0
for e in tbl:
if isinstance(e, int):
s += e
else:
# this is the trick!
s += int_sum(e)
return s
print(int_sum(tab))
You can also use sum
with recursion:
table = [7, 5, [3, 6, [2]], 7, [1, [2, 3, [4]], 9, 2], 4]
def get_sum(d):
return sum(i if isinstance(i, int) else get_sum(i) for i in d)
print(get_sum(table))
Output:
55
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