如题,我正在寻找类似于Lua的string.sub函数的Python函数,无论它是第三方还是Python标准库的一部分。我已经在互联网上搜寻了近一个小时(包括stackoverflow),但完全没有找到任何内容。
Lua:
> = string.sub("Hello Lua user", 7) -- from character 7 until the end
Lua user
> = string.sub("Hello Lua user", 7, 9) -- from character 7 until and including 9
Lua
> = string.sub("Hello Lua user", -8) -- 8 from the end until the end
Lua user
> = string.sub("Hello Lua user", -8, 9) -- 8 from the end until 9 from the start
Lua
> = string.sub("Hello Lua user", -8, -6) -- 8 from the end until 6 from the end
Lua
Python:
>>> "Hello Lua user"[6:]
'Lua user'
>>> "Hello Lua user"[6:9]
'Lua'
>>> "Hello Lua user"[-8:]
'Lua user'
>>> "Hello Lua user"[-8:9]
'Lua'
>>> "Hello Lua user"[-8:-5]
'Lua'
Python 不需要这样的函数。它的切片语法直接支持 String.sub 功能(以及更多):
>>> 'hello'[:2]
'he'
>>> 'hello'[-2:]
'lo'
>>> 'abcdefghijklmnop'[::2]
'acegikmo'
>>> 'abcdefghijklmnop'[1::2]
'bdfhjlnp'
>>> 'Reverse this!'[::-1]
'!siht esreveR'
是的,Python 提供了一个(在我看来非常好用的)子字符串选项:"string"[2:4]
返回 ri
。
请注意,这种“切片”支持多种选项:
"string"[2:] # "ring"
"string"[:4] # "stri"
"string"[:-1] # "strin" (everything but the last character)
"string"[:] # "string" (captures all)
"string"[0:6:2] # "srn" (take only every second character)
"string"[::-1] # "gnirts" (all with step -1 => backwards)
string.sub
在 Lua 中是什么作用? - John Keyes