Python 创建当存在特定类型的非重复字符时匹配的正则表达式

我正在尝试创建一个正则表达式，当没有特定类型的重复字符且忽略所有其他字符时，它将匹配。字长无关紧要。前

hippos-R-Y-S <--- Matches
hippos-R-Y-Y <--- Does not match
hippos-R-Y-P <--- Matches

---

hippos-R-Y-S这应该可以做到：

^.*?-([YRPS])-(?!\1)([YRPS])-(?!\1)(?!\2)([YRPS])$

说明：

^           : begining of string
  .*?-      : 0 or more any char until dash
  ([YRPS])  : one of the set, captured in group 1
  -         : a dash
  (?!\1)    : negative lookahead, not the same letter as in group 1
  ([YRPS])  : one of the set, captured in group 2
  -         : a dash
  (?!\1)    : negative lookahead, not the same letter as in group 1
  (?!\2)    : negative lookahead, not the same letter as in group 2
  ([YRPS])  : one of the set, captured in group 3
$           : end of string

这应该可以做到：

^.*?-([YRPS])-(?!\1)([YRPS])-(?!\1)(?!\2)([YRPS])$

说明：

^           : begining of string
  .*?-      : 0 or more any char until dash
  ([YRPS])  : one of the set, captured in group 1
  -         : a dash
  (?!\1)    : negative lookahead, not the same letter as in group 1
  ([YRPS])  : one of the set, captured in group 2
  -         : a dash
  (?!\1)    : negative lookahead, not the same letter as in group 1
  (?!\2)    : negative lookahead, not the same letter as in group 2
  ([YRPS])  : one of the set, captured in group 3
$           : end of string

您可以基于2个负lookahead使用此正则表达式跳过
[YRPS]
类中匹配的重复字符：

^[^-]+-([YRPS])(?:-(?!\1)([YRPS])(?!.*\2))+$


**正则表达式分解：*

^           # line start
[^-]+       # match 1 or more of any char that is not a -
-           # match literal -
([YRPS])    # match [YRPS] and group it #1
(?:         # start non-capturing group
   -        # match literal -
   (?!\1)   # negative lookahead to assert next char is not same as group #1
   ([YRPS]) # match [YRPS] and group it #2
   (?!.*\2) # negative lookahead to assert next char is not same as group #2
)+          # end non-capture group and + makes it match 1 or more of the same set
$           # end of line

您可以基于2个负lookahead使用此正则表达式跳过
[YRPS]
类中匹配的重复字符：

^[^-]+-([YRPS])(?:-(?!\1)([YRPS])(?!.*\2))+$


**正则表达式分解：*

^           # line start
[^-]+       # match 1 or more of any char that is not a -
-           # match literal -
([YRPS])    # match [YRPS] and group it #1
(?:         # start non-capturing group
   -        # match literal -
   (?!\1)   # negative lookahead to assert next char is not same as group #1
   ([YRPS]) # match [YRPS] and group it #2
   (?!.*\2) # negative lookahead to assert next char is not same as group #2
)+          # end non-capture group and + makes it match 1 or more of the same set
$           # end of line

字符串的格式是否始终为
^anything-[YRPS]-[YRPS]-[YRPS]$
？字符串的格式是否始终为
^anything-[YRPS]-[YRPS]$
？