Unit 2 - Binary operations in a Data Frame

 CBSE Revision Notes

Class-11 Computer Science (New Syllabus)
Unit 2: Data Handling (DH-1)

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Binary operations in a Data Frame

pandas.DataFrame.add

DataFrame.add(other, axis='columns', level=None, fill_value=None)

Addition of dataframe and other, element-wise (binary operator add).

Equivalent to dataframe + other, but with support to substitute a fill_value for missing data in one of the inputs.

Parameters:

other : Series, DataFrame, or constant axis : {0, 1, ‘index’, ‘columns’} For Series input, axis to match Series index on level : int or name Broadcast across a level, matching Index values on the passed MultiIndex level fill_value : None or float value, default None Fill existing missing (NaN) values, and any new element needed for successful DataFrame alignment, with this value before computation. If data in both corresponding DataFrame locations is missing the result will be missing

Returns:

result : DataFrame

Notes : Mismatched indices will be unioned together

Examples

>>> a = pd.DataFrame([1, 1, 1, np.nan], index=['a', 'b', 'c', 'd'],
...                  columns=['one'])
>>> a
   one
a  1.0
b  1.0
c  1.0
d  NaN
>>> b = pd.DataFrame(dict(one=[1, np.nan, 1, np.nan],
...                       two=[np.nan, 2, np.nan, 2]),
...                  index=['a', 'b', 'd', 'e'])
>>> b
   one  two
a  1.0  NaN
b  NaN  2.0
d  1.0  NaN
e  NaN  2.0
>>> a.add(b, fill_value=0)
   one  two
a  2.0  NaN
b  1.0  2.0
c  1.0  NaN
d  1.0  NaN
e  NaN  2.0

pandas.DataFrame.sub

DataFrame.sub(other, axis='columns', level=None, fill_value=None)

Subtraction of dataframe and other, element-wise (binary operator sub).

Equivalent to dataframe - other, but with support to substitute a fill_value for missing data in one of the inputs.

Parameters:

other : Series, DataFrame, or constant axis : {0, 1, ‘index’, ‘columns’} For Series input, axis to match Series index on level : int or name Broadcast across a level, matching Index values on the passed MultiIndex level fill_value : None or float value, default None Fill existing missing (NaN) values, and any new element needed for successful DataFrame alignment, with this value before computation. If data in both corresponding DataFrame locations is missing the result will be missing

Returns:

result : DataFrame

Notes : Mismatched indices will be unioned together

Examples

>>> a = pd.DataFrame([2, 1, 1, np.nan], index=['a', 'b', 'c', 'd'],
...                  columns=['one'])
>>> a
   one
a  2.0
b  1.0
c  1.0
d  NaN
>>> b = pd.DataFrame(dict(one=[1, np.nan, 1, np.nan],
...                       two=[3, 2, np.nan, 2]),
...                  index=['a', 'b', 'd', 'e'])
>>> b
   one  two
a  1.0  3.0
b  NaN  2.0
d  1.0  NaN
e  NaN  2.0
>>> a.sub(b, fill_value=0)
   one  two
a  1.0  -3.0
b  1.0  -2.0
c  1.0  NaN
d  -1.0  NaN
e  NaN  -2.0

pandas.DataFrame.mul

DataFrame.mul(other, axis='columns', level=None, fill_value=None)

Multiplication of dataframe and other, element-wise (binary operator mul).

Equivalent to dataframe * other, but with support to substitute a fill_value for missing data in one of the inputs.

Parameters:

other : Series, DataFrame, or constant axis : {0, 1, ‘index’, ‘columns’} For Series input, axis to match Series index on level : int or name Broadcast across a level, matching Index values on the passed MultiIndex level fill_value : None or float value, default None Fill existing missing (NaN) values, and any new element needed for successful DataFrame alignment, with this value before computation. If data in both corresponding DataFrame locations is missing the result will be missing

Returns:

result : DataFrame

Notes : Mismatched indices will be unioned together

pandas.DataFrame.div

DataFrame.div(other, axis='columns', level=None, fill_value=None)

Floating division of dataframe and other, element-wise (binary operator truediv).

Equivalent to dataframe / other, but with support to substitute a fill_value for missing data in one of the inputs.

Parameters:

other : Series, DataFrame, or constant axis : {0, 1, ‘index’, ‘columns’} For Series input, axis to match Series index on level : int or name Broadcast across a level, matching Index values on the passed MultiIndex level fill_value : None or float value, default None Fill existing missing (NaN) values, and any new element needed for successful DataFrame alignment, with this value before computation. If data in both corresponding DataFrame locations is missing the result will be missing

Returns:

result : DataFrame

Notes : Mismatched indices will be unioned together

pandas.DataFrame.radd

DataFrame.radd(other, axis='columns', level=None, fill_value=None)

Addition of dataframe and other, element-wise (binary operator radd).

Equivalent to other + dataframe, but with support to substitute a fill_value for missing data in one of the inputs.

Parameters:

other : Series, DataFrame, or constant axis : {0, 1, ‘index’, ‘columns’} For Series input, axis to match Series index on level : int or name Broadcast across a level, matching Index values on the passed MultiIndex level fill_value : None or float value, default None Fill existing missing (NaN) values, and any new element needed for successful DataFrame alignment, with this value before computation. If data in both corresponding DataFrame locations is missing the result will be missing

Returns:

result : DataFrame

Notes : Mismatched indices will be unioned together

Examples

>>> a = pd.DataFrame([1, 1, 1, np.nan], index=['a', 'b', 'c', 'd'],
...                  columns=['one'])
>>> a
   one
a  1.0
b  1.0
c  1.0
d  NaN
>>> b = pd.DataFrame(dict(one=[1, np.nan, 1, np.nan],
...                       two=[np.nan, 2, np.nan, 2]),
...                  index=['a', 'b', 'd', 'e'])
>>> b
   one  two
a  1.0  NaN
b  NaN  2.0
d  1.0  NaN
e  NaN  2.0
>>> a.add(b, fill_value=0)
   one  two
a  2.0  NaN
b  1.0  2.0
c  1.0  NaN
d  1.0  NaN
e  NaN  2.0

pandas.DataFrame.rsub

DataFrame.rsub(other, axis='columns', level=None, fill_value=None)

Subtraction of dataframe and other, element-wise (binary operator rsub).

Equivalent to other - dataframe, but with support to substitute a fill_value for missing data in one of the inputs.

Parameters:

other : Series, DataFrame, or constant axis : {0, 1, ‘index’, ‘columns’} For Series input, axis to match Series index on level : int or name Broadcast across a level, matching Index values on the passed MultiIndex level fill_value : None or float value, default None Fill existing missing (NaN) values, and any new element needed for successful DataFrame alignment, with this value before computation. If data in both corresponding DataFrame locations is missing the result will be missing

Returns:

result : DataFrame

Notes : Mismatched indices will be unioned together

Examples

>>> a = pd.DataFrame([2, 1, 1, np.nan], index=['a', 'b', 'c', 'd'],
...                  columns=['one'])
>>> a
   one
a  2.0
b  1.0
c  1.0
d  NaN
>>> b = pd.DataFrame(dict(one=[1, np.nan, 1, np.nan],
...                       two=[3, 2, np.nan, 2]),
...                  index=['a', 'b', 'd', 'e'])
>>> b
   one  two
a  1.0  3.0
b  NaN  2.0
d  1.0  NaN
e  NaN  2.0
>>> a.sub(b, fill_value=0)
   one  two
a  1.0  -3.0
b  1.0  -2.0
c  1.0  NaN
d  -1.0  NaN
e  NaN  -2.0