Python排序字符串以数字开头

我有下一个清单：

a = ['1th Word', 'Another Word', '10th Word']
print a.sort()
>>> ['10th Word', '1th Word', 'Another Word']

但我需要：

['1th Word', '10th Word','Another Word']

有没有一个简单的方法可以做到这一点

我试过：

r = re.compile(r'(\d+)')
def sort_by_number(s):
    m = r.match(s)
    return m.group(0)

x.sort(key=sort_by_number)

但是有些字符串没有数字，这会导致错误。 谢谢。

这通常被称为“自然排序”

见和；还有

---

关键是如果不匹配，则按原样返回字符串

import re
def natkey(s):
    return [int(p) if p else q for p, q in re.findall(r'(\d+)|(\D+)', s)]

x = ['1th Word', 'Another Word 2x', 'Another Word 20x', '10th Word 10', '2nd Word']

print sorted(x)
print sorted(x, key=natkey)

结果:

['10th Word 10', '1th Word', '2nd Word', 'Another Word 20x', 'Another Word 2x']
['1th Word', '2nd Word', '10th Word 10', 'Another Word 2x', 'Another Word 20x']

['10th Word 10', '1th Word', '2nd Word', 'Another Word 20x', 'Another Word 2x']
['1th Word', '2nd Word', '10th Word 10', 'Another Word 2x', 'Another Word 20x']