pandas.Series.align#
- Series.align(other, join='outer', axis=None, level=None, copy=True, fill_value=None, method=None, limit=None, fill_axis=0, broadcast_axis=None)[source]#
Align two objects on their axes with the specified join method.
Join method is specified for each axis Index.
- Parameters
- otherDataFrame or Series
- join{‘outer’, ‘inner’, ‘left’, ‘right’}, default ‘outer’
- axisallowed axis of the other object, default None
Align on index (0), columns (1), or both (None).
- levelint or level name, default None
Broadcast across a level, matching Index values on the passed MultiIndex level.
- copybool, default True
Always returns new objects. If copy=False and no reindexing is required then original objects are returned.
- fill_valuescalar, default np.NaN
Value to use for missing values. Defaults to NaN, but can be any “compatible” value.
- method{‘backfill’, ‘bfill’, ‘pad’, ‘ffill’, None}, default None
Method to use for filling holes in reindexed Series:
pad / ffill: propagate last valid observation forward to next valid.
backfill / bfill: use NEXT valid observation to fill gap.
- limitint, default None
If method is specified, this is the maximum number of consecutive NaN values to forward/backward fill. In other words, if there is a gap with more than this number of consecutive NaNs, it will only be partially filled. If method is not specified, this is the maximum number of entries along the entire axis where NaNs will be filled. Must be greater than 0 if not None.
- fill_axis{0 or ‘index’}, default 0
Filling axis, method and limit.
- broadcast_axis{0 or ‘index’}, default None
Broadcast values along this axis, if aligning two objects of different dimensions.
- Returns
- (left, right)(Series, type of other)
Aligned objects.
Examples
>>> df = pd.DataFrame( ... [[1, 2, 3, 4], [6, 7, 8, 9]], columns=["D", "B", "E", "A"], index=[1, 2] ... ) >>> other = pd.DataFrame( ... [[10, 20, 30, 40], [60, 70, 80, 90], [600, 700, 800, 900]], ... columns=["A", "B", "C", "D"], ... index=[2, 3, 4], ... ) >>> df D B E A 1 1 2 3 4 2 6 7 8 9 >>> other A B C D 2 10 20 30 40 3 60 70 80 90 4 600 700 800 900
Align on columns:
>>> left, right = df.align(other, join="outer", axis=1) >>> left A B C D E 1 4 2 NaN 1 3 2 9 7 NaN 6 8 >>> right A B C D E 2 10 20 30 40 NaN 3 60 70 80 90 NaN 4 600 700 800 900 NaN
We can also align on the index:
>>> left, right = df.align(other, join="outer", axis=0) >>> left D B E A 1 1.0 2.0 3.0 4.0 2 6.0 7.0 8.0 9.0 3 NaN NaN NaN NaN 4 NaN NaN NaN NaN >>> right A B C D 1 NaN NaN NaN NaN 2 10.0 20.0 30.0 40.0 3 60.0 70.0 80.0 90.0 4 600.0 700.0 800.0 900.0
Finally, the default axis=None will align on both index and columns:
>>> left, right = df.align(other, join="outer", axis=None) >>> left A B C D E 1 4.0 2.0 NaN 1.0 3.0 2 9.0 7.0 NaN 6.0 8.0 3 NaN NaN NaN NaN NaN 4 NaN NaN NaN NaN NaN >>> right A B C D E 1 NaN NaN NaN NaN NaN 2 10.0 20.0 30.0 40.0 NaN 3 60.0 70.0 80.0 90.0 NaN 4 600.0 700.0 800.0 900.0 NaN