human
I am working on the file "Python/Chapter-07/2-3-Trees-Visualization.ipynb".
The first task is:
The class Four represents a 4-node.  It manages 7 member variables:
  - mLeft    is the left subtree $l$,
  - mKeyL    is the left key $k_L$,
  - mMiddleL is the middle left subtree $m_L$,
  - mKeyM    is the middle key,
  - mMiddleR is the middle right subtree $m_R$,
  - mKeyR    is the right key $k_r$,
  - mRight   is the right subtree.
Can you write Python code for it?

Can you provide a the Python code you requested?
assistant
#Here is the Python code you requested.

class Four(TwoThreeTree):
    def __init__(self, l, kl, ml, km, mr, kr, r):
        TwoThreeTree.__init__(self)
        self.mLeft    = l
        self.mKeyL    = kl
        self.mMiddleL = ml
        self.mKeyM    = km
        self.mMiddleR = mr
        self.mKeyR    = kr
        self.mRight   = r
        
    def __str__(self):
        return self._make_string(['mLeft', 'mKeyL', 'mMiddleL', 'mKeyM', 'mMiddleR', 'mKeyR', 'mRight'])
    
    def isFour(self):
        return True