westonpace commented on a change in pull request #79: URL: https://github.com/apache/arrow-cookbook/pull/79#discussion_r720488071
########## File path: python/source/data.rst ########## @@ -137,3 +137,57 @@ function .. testoutput:: 0 .. 198 + +Searching for values matching a predicate in Arrays +--------------------------------------------------- + +If you have to look for values matching a predicate in Arrow arrays +the :mod:`arrow.compute` module provides a bunch of predicates that +can be used to find the values you are looking for. Review comment: ```suggestion If you have to look for values matching a predicate in Arrow arrays the :mod:`arrow.compute` module provides several methods that can be used to find the values you are looking for. ``` "a bunch of" is a little informal. Function might be a better word than method, I'm not sure. I think we should distinguish between "predicate" (the condition we want satisfied) and "method/function" (the tool we use to figure out what satisfies that condition). A method/function can be a predicate but I think it should return a bool (and not an array of bool) in that case. For example `lambda x: x > 10` is a predicate but `filter(lambda x: x > 10, my_list)` is not. ########## File path: python/source/data.rst ########## @@ -137,3 +137,57 @@ function .. testoutput:: 0 .. 198 + +Searching for values matching a predicate in Arrays +--------------------------------------------------- + +If you have to look for values matching a predicate in Arrow arrays +the :mod:`arrow.compute` module provides a bunch of predicates that +can be used to find the values you are looking for. + +For example, given and array with numbers from 0 to 9, if we +want to look only for those greater than 5 we could use the +func:`arrow.compute.greater` predicate and get back the elements Review comment: ```suggestion func:`arrow.compute.greater` method and get back the elements ``` ########## File path: python/source/data.rst ########## @@ -137,3 +137,57 @@ function .. testoutput:: 0 .. 198 + +Searching for values matching a predicate in Arrays +--------------------------------------------------- + +If you have to look for values matching a predicate in Arrow arrays +the :mod:`arrow.compute` module provides a bunch of predicates that +can be used to find the values you are looking for. + +For example, given and array with numbers from 0 to 9, if we Review comment: ```suggestion For example, given an array with numbers from 0 to 9, if we ``` ########## File path: python/source/data.rst ########## @@ -137,3 +137,57 @@ function .. testoutput:: 0 .. 198 + +Searching for values matching a predicate in Arrays +--------------------------------------------------- + +If you have to look for values matching a predicate in Arrow arrays +the :mod:`arrow.compute` module provides a bunch of predicates that +can be used to find the values you are looking for. + +For example, given and array with numbers from 0 to 9, if we +want to look only for those greater than 5 we could use the +func:`arrow.compute.greater` predicate and get back the elements +that fit our predicate + +.. testcode:: + + import pyarrow as pa + import pyarrow.compute as pc + + arr = pa.array(range(10)) + gtfive = pc.greater(arr, 5) + + print(gtfive.to_string()) + +.. testoutput:: + + [ + false, + false, + false, + false, + false, + false, + true, + true, + true, + true + ] + +Further more we can filter the array to get only the entries Review comment: ```suggestion Furthermore we can filter the array to get only the entries ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org