随机大写字母串中的字母

Question

我想随机大写或小写字符串中的每个字母.我是新手在python中使用字符串,但我认为因为字符串是不可变的,所以我不能执行以下操作:

i =0             
for c in sentence:
    case = random.randint(0,1)
    print("case = ", case)
    if case == 0:
        print("here0")
        sentence[i] = sentence[i].lower()
    else:
        print("here1")
        sentence[i] = sentence[i].upper()
    i += 1
print ("new sentence = ", sentence)

并得到错误:TypeError:'str'对象不支持项目分配

但那么我怎么能这样做呢？

Answer 1

您可以使用这样str.join的生成器表达式:

from random import choice
sentence = 'Hello World'
print(''.join(choice((str.upper, str.lower))(c) for c in sentence))

样本输出:

heLlo WORLd

Answer 2

构建一个新字符串.

这是一个对原始代码几乎没有变化的解决方案:

>>> import random
>>> 
>>> def randomcase(s):
...:    result = ''
...:    for c in s:
...:        case = random.randint(0, 1)
...:        if case == 0:
...:            result += c.upper()
...:        else:
...:            result += c.lower()
...:    return result
...:
...:
>>> randomcase('Hello Stackoverflow!')
>>> 'hElLo StaCkoVERFLow!'

编辑:删除我的oneliners因为我喜欢blhsing更好.