python字符串按首字母排序,Python按字母順序排序字符串，首先是小寫

I want to sort a given array of strings alphabetically using python, but lowercase words should appear first.

我想使用python按字母順序對給定的字符串數組進行排序&＃xff0c;但首先應出現小寫字。

An example:

一個例子&＃xff1a;

#!/usr/local/bin/python2.7

arr&＃61;[&＃39;A&＃39;,&＃39;e&＃39;,&＃39;a&＃39;,&＃39;D&＃39;,&＃39;f&＃39;,&＃39;B&＃39;]

arr.sort()

for s in arr: print s

Input:

輸入&＃xff1a;

A

e

a

D

f

B

Output (current):

輸出(當前)&＃xff1a;

A

B

D

a

e

f

Output (should be):

輸出(應該)&＃xff1a;

a

e

f

A

B

D

5 个解决方案

#1

6

Use a custom key method which checks whether the item is not .lower() and then compares the items itself. For &＃39;A&＃39;, &＃39;D&＃39; and &＃39;B&＃39; not x.islower() will return True and for other it is False, as True > False smaller case items will come first:

使用自定義鍵方法檢查項目是否不是.lower()&＃xff0c;然后比較項目本身。對於&＃39;A&＃39;&＃xff0c;&＃39;D&＃39;和&＃39;B&＃39;而不是x.islower()將返回True而對於其他它將為False&＃xff0c;因為True> False較小的案例項將首先出現&＃xff1a;

>>> arr &＃61; [&＃39;A&＃39;,&＃39;e&＃39;,&＃39;a&＃39;,&＃39;D&＃39;,&＃39;f&＃39;,&＃39;B&＃39;]

>>> arr.sort(key&＃61;lambda x:(not x.islower(), x))

>>> arr

[&＃39;a&＃39;, &＃39;e&＃39;, &＃39;f&＃39;, &＃39;A&＃39;, &＃39;B&＃39;, &＃39;D&＃39;]

#2

7

To sort words, and not simply letters, just swap the case:

要對單詞進行排序&＃xff0c;而不僅僅是字母&＃xff0c;只需交換案例&＃xff1a;

>>> words &＃61; [&＃39;alpha&＃39;, &＃39;Alpha&＃39;, &＃39;aLpha&＃39;, &＃39;Bravo&＃39;, &＃39;bRavo&＃39;]

>>> sorted(words)

[&＃39;Alpha&＃39;, &＃39;Bravo&＃39;, &＃39;aLpha&＃39;, &＃39;alpha&＃39;, &＃39;bRavo&＃39;]

>>> sorted(words, key&＃61;str.swapcase)

[&＃39;alpha&＃39;, &＃39;aLpha&＃39;, &＃39;bRavo&＃39;, &＃39;Alpha&＃39;, &＃39;Bravo&＃39;]

#3

3

We can use string.ascii_letters to get index of each letters to sort them.

我們可以使用string.ascii_letters來獲取每個字母的索引以對它們進行排序。

arr &＃61; [&＃39;A&＃39;,&＃39;e&＃39;,&＃39;a&＃39;,&＃39;D&＃39;,&＃39;f&＃39;,&＃39;B&＃39;]

import string

print sorted(arr, key&＃61;string.ascii_letters.index)

Results:

結果&＃xff1a;

[&＃39;a&＃39;, &＃39;e&＃39;, &＃39;f&＃39;, &＃39;A&＃39;, &＃39;B&＃39;, &＃39;D&＃39;]

Or if you want to sort the original arr list use sort built-in function.

或者&＃xff0c;如果要對原始arr列表進行排序&＃xff0c;請使用sort內置函數。

arr.sort(key&＃61;string.ascii_letters.index)

print arr

If the arr list is having words instead of single letters or alphabets we can use str.swapcase

如果arr列表中有單詞而不是單個字母或字母&＃xff0c;我們可以使用str.swapcase

arr &＃61; [&＃39;Abc&＃39;, &＃39;abc&＃39;, &＃39;aBc&＃39;]

print sorted(arr, key&＃61;str.swapcase)

Yields:

產量&＃xff1a;

[&＃39;abc&＃39;, &＃39;aBc&＃39;, &＃39;Abc&＃39;]

#4

1

Some timings show that for sorting single characters creating a dict is the actually most efficient:

一些時間表明&＃xff0c;對於排序單個字符創建一個字典實際上是最有效的&＃xff1a;

python2.7:

python2.7&＃xff1a;

from string import ascii_letters

d &＃61; {b:a for a, b in enumerate(ascii_letters)}

In [34]: timeit sorted(s, key&＃61;str.swapcase)

10 loops, best of 3: 32.6 ms per loop

In [35]: timeit sorted(s,key&＃61;lambda x: (not x.islower(),x))

10 loops, best of 3: 51.4 ms per loop

In [37]: timeit (sorted(s ,key&＃61;d.get))

10 loops, best of 3: 22.4 ms per loop

Python3.4:

Python3.4&＃xff1a;

In [4]: timeit sorted(s,key&＃61;lambda x: (not x.islower(),x))

10 loops, best of 3: 57.7 ms per loop

In [5]: timeit sorted(s, key&＃61;str.swapcase)

10 loops, best of 3: 41.2 ms per loop

In [6]: timeit (sorted(s ,key&＃61;d.get))

10 loops, best of 3: 21.1 ms per loop

#5

0

Given : Alphanumeric string

給定&＃xff1a;字母數字字符串

Aim: To sort by rules

目標&＃xff1a;按規則排序

Small letters first.

首先是小寫字母。

Then capital letters.

然后大寫字母。

Then digits (even first, odd last) (Least priority).

然后是數字(甚至是第一個&＃xff0c;最后一個奇數)(最低優先級)。 def func(l):

if l.islower():

return ord(l) - 32

elif l.isupper():

return ord(l) &＃43; 32

elif l.isdigit():

if int(l) % 2 &＃61;&＃61; 0:

return ord(l) &＃43; 200

else:

return ord(l) &＃43; 100

print(*sorted(st, key&＃61;func), sep&＃61;&＃39;&＃39;)