code: def _compile(pattern, flags):
      # internal: compile pattern
      if isinstance(flags, RegexFlag):
          flags = flags.value
      try:
          return _cache[type(pattern), pattern, flags]
      except KeyError:
          pass
      if isinstance(pattern, Pattern):
          if flags:
              raise ValueError(
                  "cannot process flags argument with a compiled pattern"
              )
          return pattern
      if not _compiler.isstring(pattern):
          raise TypeError(
              "first argument must be string or compiled pattern"
          )
      if flags & T:
          import warnings
  
          warnings.warn(
              "The re.TEMPLATE/re.T flag is deprecated "
              "as it is an undocumented flag "
              "without an obvious purpose. "
              "Don't use it.",
              DeprecationWarning,
          )
      p = _compiler.compile(pattern, flags)
      if not (flags & DEBUG):
          if len(_cache) >= _MAXCACHE:
              # Drop the oldest item
              try:
                  del _cache[next(iter(_cache))]
              except (StopIteration, RuntimeError, KeyError):
                  pass
          _cache[type(pattern), pattern, flags] = p
      return p
  
imports: import enum
  from .None import _compiler, _parser
  import functools
  import copyreg
label_desc: Use image node_id 13 for calling a global function with example usage: _compile(pattern, flags) and returns: p, _cache, pattern