def _row_norm(df):
    """
    >>> df = pd.DataFrame({
    ...   'cell-1': {'a':8, 'b':1, 'c': 7},
    ...   'cell-2': {'a':1, 'b':1, 'c': 1},
    ...   'cell-3': {'a':10, 'b':1, 'c': 10}
    ... })
    >>> _row_norm(df)
       cell-1  cell-2  cell-3
    a     0.8     0.1     1.0
    b     1.0     1.0     1.0
    c     0.7     0.1     1.0
    """
    t = df.T
    return (t / t.max()).T