expr: Summary
expr: summary hashable and eval(str(.)) able
python: Summary compute
scalar: name, dtype properties
expr: Reductions support Number interface
compute: python arithmetic
python: summary by
pandas: summary by tests
pandas: summary by
pandas: summary
sql: summary and by summary
expr: name attribute for TableExpr

in case a TableExpr is a column
spark: summary
don't test base spark

Sadly we can have only one SparkContext
python: refactor out split-apply-combine reduceby funcs

These will be used in spark
spark: by uses combineByKey, not groupByKey
fix imports
expr: summary docstring
remove old binop/unaryop implementations
into: Collection <- accepts kwargs