Question

我正在制作科学记谱法，所以让我给你看一下代码：

import time

def scientific_notation(number):
    decimal = ""
    for thing in str(number):
        """
        Loops through the number to add stuff to "decimal"
        (probably not necessary but i'm going to keep it 
        there in case I need a filter.)
        """
        if len(decimal) == len(str(number)):
            break
        else:
            decimal += thing
    decimal = decimal.replace('0','')
    print(decimal)
    while float(decimal) > 10:
        # Uses decimal notation
        actual = ''
        # To keep track of the original place
        for x in range(0,len(str(number))):
            actual += str(number)[x]
            decimal = decimal.replace(str(number)[x],str(number)[x]+'.')
            # Adding decimal points to each place until the float version of that is less than 10
            if decimal.count('.') > 1:
                # if there's more than one decimal, replace that value with what it was before
                decimal = decimal.replace(str(number)[x],actual)
            elif float(decimal) > 10:
                # if the float version of the decimal is more than 10, wait for the while loop to realize that by doing nothing
                pass
            else:
                pass
    else:
        # Output
        power = '10^'+str(str(number).count('0'))
        print(decimal+" * "+power)


scientific_notation(102)

好吧，既然你已经看了它，那就让我告诉你发生了什么。

因此，在while循环中，我的if语句不执行

if decimal.count('.') > 1

或者至少，没有正确执行，导致

ValueError: could not convert string to float: '1.102.'

因为我的while循环尝试将其转换为浮点数，但得到的是＆＃39; 1.102。＆＃39;并引发ValueError，因为您无法将带有两个小数点的内容转换为float。关于为什么if语句不起作用的任何想法？我不知道，也许我只是愚蠢。

Answer 1

Eek你的代码是可怕的，并立即做了一些意想不到的事情。例如：

decimal = ""
for thing in str(number):
    """
    Loops through the number to add stuff to "decimal"
    (probably not necessary but i'm going to keep it 
    there in case I need a filter.)
    """
    if len(decimal) == len(str(number)):
        break
    else:
        decimal += thing

与

相同

decimal = str(number)

也

decimal = decimal.replace('0','')

这会将102变为12，而这不是故意的。

让我们看一个不同的算法，并用算术而不是字符串操作来处理它。

def scientific_notation(number):
    n = 0
    while number > 10:
        n += 1
        number /= 10
    print(f"{number} * 10^{n}")

>>> scientific_notation(102)
1.02 * 10^2

故障安全无法正确执行

1 个答案: