读取文件并打印出文件中数字总和的程序。该文件包含单个以逗号分隔的浮点数

Question

例如，如果您的文件包含：

-2.5, 2.0
8.0
100.0, 3.0, 5.1, 3.6
6.5

那么您的程序示例运行将如下所示：

Please enter your file name:  nums.txt
The sum of your numbers is 125.7.

我有运行程序，但它给我一个错误，说 “sum_number = sum_number + 浮动（i） ValueError：无法将字符串转换为浮点数：'.'"

任何帮助将不胜感激！

filename = input("Please enter your file name: ")
sum_number = 0
openthefile = open(filename, "r")

for i in openthefile:
    Split = i.split(',')
    Join = "".join(Split)
    print(Join)

for i in Join:
    sum_number = sum_number + float(i)

print("The sum of your numbers is",sum_number)

Answer 1

filename = input("Please enter your file name: ")

lst = []
with open(filename, 'r') as f:
    for line in f:
        lst.extend(line.split(','))

lst = map(float, lst)

print(sum(lst))  # 125.7

这将创建一个空列表，然后对于每一行，将通过逗号拆分该行获得的元素添加到列表中。最后两步将元素转换为浮点数并打印总和。

或者，不跟踪列表中的所有元素，只跟踪总和：

filename = input("Please enter your file name: ")

total = 0
with open(filename, 'r') as f:
    for line in f:
        for elem in line.split(','):
            total += float(elem)

print(total)  # 125.7

Answer 2

您可以按照以下方式进行：

filename = input("Please enter your file name: ")
sum_number = 0
openthefile = open(filename, "r")

for line in openthefile:
    for num in line.split(','):
        sum_number = sum_number + float(num.strip())

print("The sum of your numbers is %.1f" %(sum_number))

我们简单地循环遍历文件的每一行，用 , 拆分行上的所有值，并将每一行上的每个值添加到我们的总和中。最后，我们打印出值。

Answer 3

您可以将 map 和 sum 与生成器表达式一起使用：

filename = input("Please enter your file name: ")

with open(filename) as f: # closes your file automatically
    print("The sum of your numbers is {:.1f}".format(sum(sum(map(float, line.split(","))) for line in f)))

The sum of your numbers is 125.7

您正在尝试连接所有花车然后投射即：

float("100.03.05.13.6")

因此，对于 for i in Join:，您将迭代连接字符串的每个字符，这会给出您看到的错误，因为 . 无法转换为浮点数。

{:.1f} 格式保留一位小数。

Answer 4

您可以使用生成器打印所有值的总和

with open(filename,"r")as f:
    print sum(float(e) for line in f for e in line.split(","))

>> 125.7

读取文件并打印出文件中数字总和的程序。该文件包含单个以逗号分隔的浮点数

A program to read a file and print out the sum of the numbers in the file. The file contains a single floating point numbers separated by commas

python

text

file