如何存储在Python中作为输出生成的数字列表？

Question

Suppose I want to add several numbers together like: 1. Find even numbers between 1-100. 2. Find odd numbers between 2-200. 3. Add them.

So for this, I can check for even numbers and odd numbers respectively, but to add them, they must be stored somewhere. Now how can I do this?

ie store the output of the first step, store the output of second step and then add them together.

Answer 1

Find even numbers between 1-100:

>>> l = [i for i in range(1,101) if i % 2 == 0]
>>> print l
[2, 4, 6, ..., 100]

Find odd numbers between 2-200:

>>> l2 = [i for i in range(2,200) if i % 2 != 0]
>>> print l2
[3, 5, 7, ..., 199]

Find the sum:

>>> total = sum(l) + sum(l2)
>>> print total
12540

What I've done is List Comprehensions, a loop which creates values for whatever factors you want. Here's a link to the documentation about it: http://docs.python.org/2/tutorial/datastructures.html#list-comprehensions

Answer 2

Even Numbers List:

a = [i for i in range(2,101,2)]

Odd Numbers List:

b = [i for i in range(3,200,2)]

Sum:

c = sum(a) + sum(b)

Answer 3

This is what containers like lists are for:

numbers = []  # Setup an empty list

for number in range(10):  # Loop over your numbers
    numbers.append(number)  # Append the number to your list

print sum(numbers)  # 45

Answer 4

Results of first and second steps can be stored in 2 different lists.

list1 = [2, 4, 6 .. ]
list2 = [1, 3, 5 .. ]

Lists are documented on python docs at http://docs.python.org/2/tutorial/datastructures.html#more-on-lists

Answer 5

You don't really need a list.

>>> sum(x for x in range(1,100) if x % 2)
2500
>>> sum(x for x in range(2,200) if not x % 2)
9900