将浮点数分开 [英] Separate float into digits

问题描述

我有一个浮游物:

pi = 3.141

并想将浮点数字分开，并以如下整数形式将它们放入列表中:

And want to separate the digits of the float and put them into a list as intergers like this:

#[3, 1, 4, 1]

我知道将它们分开并放在列表中，但是作为字符串，这对我没有帮助

I know to to separate them and put them into a list but as strings and that doesnt help me

推荐答案

您需要遍历数字的字符串表示形式，并检查数字是否为数字.如果是，则将其添加到列表中.这可以通过使用列表理解来完成.

You need to loop through the string representation of the number and check if the number is a digit. If yes, then add it to the list. This can be done by using a list comprehension.

>>> pi = 3.141
>>> [int(i) for i in str(pi) if i.isdigit()]
[3, 1, 4, 1]

使用正则表达式的另一种方式(不推荐)

Another way using Regex (Not - preffered)

>>> map(int,re.findall('\d',str(pi)))
[3, 1, 4, 1]

最后的方法-蛮力

>>> pi = 3.141
>>> x = list(str(pi))
>>> x.remove('.')
>>> map(int,x)
[3, 1, 4, 1]

文档中的参考文献很少

• str.isdigit
• re.findall
• map

timeit结果

python -m timeit "pi = 3.141;[int(i) for i in str(pi) if i.isdigit()]"
100000 loops, best of 3: 2.56 usec per loop
python -m timeit "s = 3.141; list(map(int, str(s).replace('.','')))" # Avinash's Method
100000 loops, best of 3: 2.54 usec per loop
python -m timeit "import re;pi = 3.141; map(int,re.findall('\d',str(pi)))"
100000 loops, best of 3: 5.72 usec per loop
python -m timeit "pi = 3.141; x = list(str(pi));x.remove('.'); map(int,x);"
100000 loops, best of 3: 2.48 usec per loop

如您所见，蛮力方法是最快的.正则表达式的答案是最慢的.

As you can see the brute force method is the fastest. The Regex answer as known is the slowest.

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