might be a dumb question but why when I try to use map() function on an already existing list:
nums = [1,2,3,4,5]
result = map(lambda num: num+num , nums)
print(result)
it returns me: <map object at 0x7f41cef17130> , instead of my result;
on the contrary when I do this:
nums = 1,2,3,4,5
result = list(map(lambda num: num+num , nums))
print(result)
it does print me my desired result: [2, 4, 6, 8, 10]
Others have already said this. In python you have a few datatypes that don't show the values directly and require another function. This is one of them. Others are a generator:
(x for x in range(5))
<generator object at ....>
And zip:
zip([1,2], [1,2])
<zip at ....>
What that means is basically where in the memory it is saved
In general just know that whenever you see python return something like that, but you wanted a datatype (like a list or a string), that means you still need to do something to it. So:
list(map(...))
list(zip(...))
etc.
mapreturns amapobject always.mapobjects are iterators. You need to iterate over the object to get each individual value. One way is to create alistout of it, or atuple, or whatever you want.map()was called on an "existing list", just if you calledlist()on the result ofmap().