python如何实现数组元素两两相加

count = 0
c2 = []
for i in range(len(c)):
    if count == 0:
        
        mm = c[i]
        #print(mm)
        #print(count)
    if count == 1:
        print(c[i])
        value = c[i] + mm
        c2 = np.append(c2,value)
        count = 0
        mm = 0
        value = 0
        continue
    count = count + 1 

# -*- coding:utf-8 -*-
def quick_sort(arr, left, right):
    """快速排序"""
    if left >= right:
        return
    low = left
    high = right
    p = arr[left]
    while left < right:
        while left < right and arr[right] >= p:
            right -= 1
        arr[left] = arr[right]
        while left < right and arr[left] <= p:
            left += 1
        arr[right] = arr[left]
    arr[left] = p
    quick_sort(arr, low, left-1)
    quick_sort(arr, left+1, high)
def find_sum(arr, sum):
    """寻找数组中相加等于sum的组合"""
    quick_sort(arr, 0, len(arr) - 1)
    begin, end = 0, len(arr) - 1
    while begin < end:
        if arr[begin] + arr[end] < sum:
            begin += 1
        elif arr[begin] + arr[end] > sum:
            end -= 1
        else:
            print('%s %s' % (arr[begin], arr[end]))
            begin += 1
            end -= 1
if __name__ == '__main__':
    arr = [1, 7, 17, 2, 6, 3, 14]
    find_sum(arr, 20)