def index(self, i, length=None):
        """Return an integer index or None"""
        if self.begin <= i <= self.end:
            index = i - self.BEGIN - self.offset
            if length is None:
                length = self.full_range()
            else:
                length = min(length, self.full_range())

            if 0 <= index < length:
                return index
def index(self, i, length=None):
        """Return an integer index or None"""
        if self.begin <= i <= self.end:
            index = i - self.BEGIN - self.offset
            if length is None:
                length = self.full_range()
            else:
                length = min(length, self.full_range())

            if 0 <= index < length:
                return index
def index ( self , i , length = None ) : if self . begin <= i <= self . end : index = i - self . BEGIN - self . offset if length is None : length = self . full_range ( ) else : length = min ( length , self . full_range ( ) ) if 0 <= index < length : return index
Return an integer index or None
Return an integer index or None