Improve groupby apply

Improve groupby apply (#24)

* refactor pandas like utils

* fix groupby apply

refactor pandas like utils

0.2.6

refactor pandas like utils (#23)

Avoid using pd.df.empty

Avoid using df.empty (#22)

* Add pandas like utils

* add safe group apply

* handle empty cols

* add comments

* update none safe logic

* avoid using df.empty

Update none logic for pandas like utils

Update none safe logic (#21)

* Add pandas like utils

* add safe group apply

* handle empty cols

* add comments

* update none safe logic

Add safe_groupby_apply

add safe group by apply (#20)

* Add pandas like utils

* add safe group apply

* handle empty cols

* add comments

Add pandas like utils

0.2.2

Add pandas like utils (#19)

Improve Schema

Improve schema (#18)

* add write protection to ParamDict

* update

* add more functions to pyarrow

* update

* add comments

* bump up version

* EmptyAwareIterable empty()-> empty

* add index support for ParamDict

* version

* support null type

* update

* Improve schema

Support null type

Support null type (#17)

* add write protection to ParamDict

* update

* add more functions to pyarrow

* update

* add comments

* bump up version

* EmptyAwareIterable empty()-> empty

* add index support for ParamDict

* version

* support null type

* update

Add index support for ParamDict

Add index support for ParamDict (#16)

* add write protection to ParamDict

* update

* add more functions to pyarrow

* update

* add comments

* bump up version

* EmptyAwareIterable empty()-> empty

* add index support for ParamDict

* version

Update comments

Update comments (#15)

* add write protection to ParamDict

* update

* add more functions to pyarrow

* update

* add comments

* bump up version