如何读取python文本文件中的数字？

我在写一个程序，在这个程序中，我根据存储在文件中的数字进行简单的计算。但是，它会不断返回ValueError。代码中是否有我应该更改的内容或文本文件的编写方式

该文件是：

def main():

    number = 0
    total = 0.0
    highest = 0
    lowest = 0

    try:
        in_file = open("donations.txt", "r")

        for line in in_file:
            donation = float(line)

            if donation > highest:
                highest = donation

            if donation < lowest:
                lowest = donation

            number += 1
            total += donation

            average = total / number

        in_file.close()

        print "The highest amount is $%.2f" %highest
        print "The lowest amount is $%.2f" %lowest
        print "The total donation is $%.2f" %total
        print "The average is $%.2f" %average

    except IOError:
        print "No such file"

    except ValueError:
        print "Non-numeric data found in the file."

    except:
        print "An error occurred."

main()

---

如果你看不懂一行，跳到下一行

for line in in_file:
    try:
        donation = float(line)
    except ValueError:
        continue

稍微清理一下您的代码

with open("donations.txt", "r") as in_file:
    highest = lowest = donation = None
    number = total = 0
    for line in in_file:
        try:
            donation = float(line)
        except ValueError:
            continue
        if highest is None or donation > highest:
            highest = donation

        if lowest is None or donation < lowest:
            lowest = donation

        number += 1
        total += donation

        average = total / number

print "The highest amount is $%.2f" %highest
print "The lowest amount is $%.2f" %lowest
print "The total donation is $%.2f" %total
print "The average is $%.2f" %average

打开（“investments.txt”、“r”），如_文件中所示：
最高=最低=捐赠=无
数字=总数=0
对于\u文件中的行：
尝试：
捐赠=浮动（行）
除值错误外：
持续
如果“最高”为“无”或“捐赠>最高”：
最高=捐款
如果最低值为无或<最低值：
最低=捐赠
数字+=1
总数+=捐款
平均数=总数/数量
打印“最高金额为%.2f”%highest
打印“最低金额为%.2f”%lowest
打印“捐赠总额为%.2f$”%total
打印“平均值为$%.2f”%average

当它读取“John Brown”行时会发生什么？似乎你没有跳过每一行，这只是一个名字。但它第一次定义的最高时间在哪里？可能重复

with open("donations.txt", "r") as in_file:
    highest = lowest = donation = None
    number = total = 0
    for line in in_file:
        try:
            donation = float(line)
        except ValueError:
            continue
        if highest is None or donation > highest:
            highest = donation

        if lowest is None or donation < lowest:
            lowest = donation

        number += 1
        total += donation

        average = total / number

print "The highest amount is $%.2f" %highest
print "The lowest amount is $%.2f" %lowest
print "The total donation is $%.2f" %total
print "The average is $%.2f" %average