Question

我在

列中有一个数字列表

10,12,13

我想编写一个python程序，可以通过以下方式添加这些数字：10+12=22, 10+13=23, 12+13=25 任何人都可以提出任何建议如何做到这一点。感谢

Answer 1

使用combinations中的itertools，这可以相当简单地完成。对于列表a，您可以获得此类n元素的所有总和

from itertools import combinations

def sum_of_size(a, n):
    return map(sum, combinations(a, n))

编辑：如果您使用的是python 3，请改用

from itertools import combinations

def sum_of_size(a, n):
    return list(map(sum, combinations(a, n)))

用你的例子

sum_of_size([10, 12, 13], 2)
# => [22, 23, 25]

Answer 2

这可能有效（使用Python 2.7）：

x = [10,12,13]
for i in range(len(x)):
    for j in range(i+1, len(x)):
        print x[i],' + ', x[j], ' = ', x[i]+x[j]

输出：

10  +  12  =  22
10  +  13  =  23
12  +  13  =  25

<强>更新假设文件有一行：10,12,13

import csv

f = open("test.dat", 'r')
try:
    reader = csv.reader(f)
    for row in reader:
        # convert array of string to int
        # http://stackoverflow.com/a/7368801/5916727
        # For Python 3 change the below line as explained in above link
        # i.e. results = list(map(int, results))
        results = map(int, row)
        for i in range(len(results)): 
            for j in range(i+1, len(results)): 
                print (results[i]+results[j])
finally:
    f.close()

Answer 3

如果您因某种原因不想使用itertools，那么就可以实现这一点。我假设您通过示例结果做了您想做的事情： -

ColumnOfNumbers = [10,12,13]

def ListAddition(ColumnOfNumbers):

    #check if the list is longer than one item
    if len(ColumnOfNumbers)<=1:
        return "List is too short"

    #Define an output list to append results to as we iterate
    OutputList = []
    #By removing a number from the list as we interate we stop double results
    StartNumber = 0

    #Create a function to iterate - this is one less than the length of the list as we need pairs.
    for x in range(len(ColumnOfNumbers)-1):
        #Remove the first number from the list and store this number
        StartNumber = ColumnOfNumbers[0]
        ColumnOfNumbers.pop(0)

        #Iterate through the list adding the first number and appending the result to the OutputList
        for y in ColumnOfNumbers:
            OutputList.append(StartNumber + y)
    return OutputList

#Call the List Addition Function 
print (ListAddition(ColumnOfNumbers))

如果你想让python从一个数字列的文件中生成这个列表，那么试试这个： -

ColumnOfNumbers = []
file1 = open('test.dat','r')
for line in file1:
    ColumnOfNumbers.append(int(line))

在python中的列中添加数字

3 个答案: