Version 0.23.0

NumPy's universal function (ufunc) compatibility

We added the compatibility of NumPy ufunc (#1096, #1106). Virtually all ufunc compatibilities in Koalas Series were implemented. See the example below:

>>> import databricks.koalas as ks
>>> import numpy as np
>>> kdf = ks.range(10)
>>> kser = np.sqrt(kdf.id)
>>> type(kser)
<class 'databricks.koalas.series.Series'>
>>> kser
0    0.000000
1    1.000000
2    1.414214
3    1.732051
4    2.000000
5    2.236068
6    2.449490
7    2.645751
8    2.828427
9    3.000000

Other new features and improvements

We added the following new features:

koalas:

• option_context (#1077)

koalas.DataFrame:

• where (#1018)
• mask (#1018)
• iterrows (#1070)

koalas.Series:

• pop (#866)
• first_valid_index (#1092)
• pct_change (#1071)

koalas.Index

• symmetric_difference (#953, #1059)
• to_numpy (#1058)
• transpose (#1056)
• T (#1056)
• dropna (#938)
• shape (#1085)
• value_counts (#949)

koalas.MultiIndex:

• symmetric_difference (#953, #1059)
• to_numpy (#1058)
• transpose (#1056)
• T (#1056)
• dropna (#938)
• shape (#1085)
• value_counts (#949)

Other improvements

• Fix comparison operators to treat NULL as False (#1029)
• Make corr return koalas.DataFrame (#1069)
• Include link to Help Thirsty Koalas Fund (#1082)
• Add Null handling for different frames (#1083)
• Allow Series.__getitem__ to take boolean Series (#1075)
• Produce correct output against multiIndex when 'compute.ops_on_diff_frames' is enabled (#1089)
• Fix idxmax() / idxmin() for Series work properly (#1078)