parameters: (self, b)
docstring: Read bytes into a pre-allocated bytes-like object b.
  
          Returns an int representing the number of bytes read (0 for EOF), or
          None if the object is set not to block and has no data to read.
docstring_summary: Read bytes into a pre-allocated bytes-like object b.
docstring_tokens: Read bytes into a pre - allocated bytes - like object b .
function: def readinto(self, b):
          """Read bytes into a pre-allocated bytes-like object b.
  
          Returns an int representing the number of bytes read (0 for EOF), or
          None if the object is set not to block and has no data to read.
          """
          self._unsupported("readinto")
function_tokens: def readinto ( self , b ) : self . _unsupported ( "readinto" )