使用整数和单词对字符串进行排序,而不改变其位置

Question

说我有一个字符串a.

a = "12 I have car 8 200 a"

我需要以输出应该这样的方式对这个字符串进行排序

8 a car have 12 200 I

即,对字符串进行排序,使所有单词按字母顺序排列,所有整数按数字顺序排列.此外,如果字符串中的第n个元素是整数,则它必须保持整数,如果是单词则必须保留为单词.

这是我试过的.

a = "12 I have car 8 200 a"


def is_digit(element_):
    """
    Function to check the item is a number. We can make using of default isdigit function
    but it will not work with negative numbers.
    :param element_:
    :return: is_digit_
    """
    try:
        int(element_)
        is_digit_ = True
    except ValueError:
        is_digit_ = False

    return is_digit_



space_separated = a.split()

integers = [int(i) for i in space_separated if is_digit(i)]
strings = [i for i in space_separated if i.isalpha()]

# sort list in place
integers.sort()
strings.sort(key=str.lower)

# This conversion to iter is to make use of next method.
int_iter = iter(integers)
st_iter = iter(strings)

final = [next(int_iter) if is_digit(element) else next(st_iter) if element.isalpha() else element for element in
         space_separated]

print " ".join(map(str, final))
# 8 a car have 12 200 I

我得到了正确的输出.但我使用两个单独的排序函数来排序整数和单词(我认为这是昂贵的).

是否可以使用单个排序函数进行整个排序？

Answer 1

numpy 允许更简洁地编写它，但并没有消除对两种单独排序的需要：

$ python3
Python 3.5.2 (default, Nov 23 2017, 16:37:01) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy as np
>>> from numpy.core.defchararray import isdecimal, lower
>>> 
>>> s = "12 I have car 8 200 a"
>>> 
>>> a = np.array(s.split())
>>> 
>>> integer_mask = isdecimal(a)
>>> string_mask = ~integer_mask
>>> strings = a[string_mask]
>>> 
>>> a[integer_mask] = np.sort(np.int_(a[integer_mask]))
>>> a[string_mask]  = strings[np.argsort(lower(strings))]
>>> 
>>> ' '.join(a)
'8 a car have 12 200 I'