仅当小数点不是整数时如何显示小数点? [英] How to show decimal point only when it's not a whole number?

问题描述

我用谷歌搜索过，但找不到正确的答案.

I have Googled, but couldn't find a proper answer to this.

假设我们有浮点数并且我们得到了它们的平均值.他们的平均值是这样的:

Let's say we have floats and we get their averages. Their averages are like this:

3.5
2.5
5
7

所以我们有 4 个号码(不再在列表中).两个带小数和两个整数的数字.

So we've got 4 numbers (who are not in a list anymore). Two numbers with a decimal and two whole numbers.

我想做的是，打印这些数字并保持这样.不过，我的问题是，当我使用 %.1f 时，它会从 5 和 7 生成 5.0 和 7.0，而我想保持它们原样 (因此将它们作为一个整体保留号).

What I want to do is, to print these numbers and keep them like this. My problem is, though, that when I use %.1f, it makes 5.0 and 7.0 from 5 and 7, while I want to keep them as they are (so keep them as a whole number).

所以我想按原样打印它们，但我不知道如何打印.Float 将 decimal 点添加到整数.将它们转换为 int，删除所需的小数.

So I'd like to print them exactly as they are, but I don't know how. Float adds decimal points to whole numbers. Converting them to an int, removes the needed decimals.

这两个选项都不是我想要的.

Both options are not what I want.

有人能指出我正确的方向吗?

Can someone point me in the right direction?

相关代码，如问:

# I have a list of numbers and I am calculating their average and rounding them first.
get_numbers = map(float, line[-1])
average_numbers = sum(get_numbers) / len(get_numbers)
rounded_numbers= round(average_numbers * 2) / 2

# So now, I've got the numbers: 3.5, 2.5, 5, 7

print "The numbers are: %.1f" % (rounded_numbers)

推荐答案

您可以使用浮动的 is_integer 方法.如果浮点数可以表示为整数(换句话说，如果它的形式为 X.0)，则返回 True:

You can use floats' is_integer method. It returns True if a float can be represented as an integer (in other words, if it is of the form X.0):

li = [3.5, 2.5, 5.0, 7.0]

print([int(num) if float(num).is_integer() else num for num in li])
>> [3.5, 2.5, 5, 7]

编辑

在 OP 添加他们的代码之后:

After OP added their code:

不要像在上面的原始示例中那样使用列表推导式，您应该对计算的平均值使用相同的逻辑:

Instead of using list comprehension like in my original example above, you should use the same logic with your calculated average:

get_numbers = map(float, line[-1])  # assuming line[-1] is a list of numbers
average_numbers = sum(get_numbers) / len(get_numbers)
average = round(average_numbers * 2) / 2
average = int(average) if float(average).is_integer() else average
print average  # this for example will print 3 if the average is 3.0 or
               # the actual float representation. 

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