MulDataFrameOperators and compatibility#
Operators can be used with MulDataFrame and MulSeries.
>>> mf
(3, 2) g 7 6
f 5 3
c d
-------- ---------
x y c d
a 1 2 a 1 2
b 3 6 b 8 9
b 5 6 b 8 7
>>> mf-1
(3, 2) g 7 6
f 5 3
c d
-------- ---------
x y c d
a 1 2 a 0 1
b 3 6 b 7 8
b 5 6 b 7 6
>>> (mf**2).iloc[1,0]
64
Except for the = operator, all operators are implemented using the Call method with the special operator methods of the values series or dataframe as the input (see Pandas methods). For example, the + operator is implemented as:
>>> class MulDataFrame:
...
def __add__(self,other):
return self.call('__add__',other)
...
The = operator is implemented using the .equals method as input.
Because of the use of the call method, an operation is only valid if:
the operation is a valid operation on the underlying values series or dataframe(s).
the result of the operation on the values series or dataframe(s) satisfies the index matching rules.
For example, the + operation below works on the values dataframes of the two muldataframes but does not work on the muldataframes themselves:
>>> mf2
(2, 2) f 5 3
c d
-------- ---------
y c d
a 2 a 1 2
b 6 b 8 9
>>> mf3
(2, 2) f 5 3
c d
-------- ---------
y c d
a 2 a 1 2
c 6 c 8 9
>>> mf2.df + mf3.df
c d
a 2.0 4.0
b NaN NaN
c NaN NaN
>>> mf2 + mf3
NotImplementedError
Also becuase of the call method, when two muldataframes are operated, the result inherits the index or/and columns of the first muldataframe and ignore the index and columns of the second.
>>> mf+mf2
(3, 2) g 7 6
f 5 3
c d
-------- ---------
x y c d
a 1 2 a 2 4
b 3 6 b 16 18
b 5 6 b 16 16
>>> mf2+mf
NotImplementedError
Of note, the mf2+mf in the above example does not work because the addition result of the values dataframes does not satisfy the index mathcing rules of mf2 while it does satisfy the rules of mf.
Compatibility with pandas#
As all operators (except for =) are implemented using the Call method, they can be used between a pandas object and a MulDataFrame object. The order in which a pandas object and a MulDataFrame object are operated on does not matter!
>>> mf2 / mf2.df
(2, 2) f 5 3
c d
-------- -----------
y c d
a 2 a 1.0 1.0
b 6 b 1.0 1.0
>>> mf2.df / mf2
(2, 2) f 5 3
c d
-------- -----------
y c d
a 2 a 1.0 1.0
b 6 b 1.0 1.0