我正在寻找用于替换字符串的第一个和最后一个字的最
pythonic方式(在字母的基础上执行它不会因各种原因而起作用).为了演示我正在尝试做什么,这是一个例子.
a = "this is the demonstration sentence."
我希望我的python函数的结果是：
b = "This is the demonstration Sentence."
其中棘手的部分是字符串的前端或末端可能有空格.我需要保留这些.
这就是我的意思：
a = " this is a demonstration sentence. "
结果需要是：
b = " This is a demonstration Sentence. "
也会对正则表达式是否比python的内置方法更好地完成这项工作的意见感兴趣,反之亦然.
解决方法
import re
a = " this is a demonstration sentence. "
print(re.sub(r'''(?x) # VERBOSE mode
( #
^ # start of string
\s* # zero-or-more whitespaces
\w # followed by an alphanumeric character
)
| # OR
(
\w # an alphanumeric character
\S* # zero-or-more non-space characters
\s* # zero-or-more whitespaces
$ # end of string
)
''',lambda m: m.group().title(),a))
产量
This is a demonstration Sentence.