# Annotate\_variants\_table using keytable generated from spark dataframe

**URL:** <https://discuss.hail.is/t/annotate-variants-table-using-keytable-generated-from-spark-dataframe/310>\
**Category:** Help \[0.1\]\
**Created:** [October 8, 2017, 3:25pm UTC](https://discuss.hail.is/t/annotate-variants-table-using-keytable-generated-from-spark-dataframe/310 "2017-10-08T15:25:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jerryliu2005](https://yyz2.discourse-cdn.com/flex036/user_avatar/discuss.hail.is/jerryliu2005/32/97_2.png) [@jerryliu2005](https://discuss.hail.is/u/jerryliu2005)\
**Post date:** [October 8, 2017, 3:25pm UTC](https://discuss.hail.is/t/annotate-variants-table-using-keytable-generated-from-spark-dataframe/310/1 "2017-10-08T15:25:35Z")

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Hello,  
I have a keytable generated from a Spark dataframe with the ‘v’ column in the string format (eg. ‘1:20000:A:T’)  
kt  
Out[206]: KeyTable(is.hail.HailContext@7cf3114c,MapPartitionsRDD[99] at map at KeyTable.scala:54,Struct{gene\_refgene:String,func\_refgene:String,exonicfunc\_refgene:String,popfreqmax:Double,mutationtaster\_score:Double,v:String},[Ljava.lang.String;@4d842e97)  
kt.key  
[u’v’]

The annotate\_variants\_table method doesn’t work for me as it expects the table keyed by “Variant.” I know you can use Variant.parse() but don’t know how to convert the column type in the key table.

Please help. Thx!

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**Author:** ![konradjk](https://yyz2.discourse-cdn.com/flex036/user_avatar/discuss.hail.is/konradjk/32/12_2.png) [@konradjk](https://discuss.hail.is/u/konradjk)\
**Post date:** [October 8, 2017, 3:55pm UTC](https://discuss.hail.is/t/annotate-variants-table-using-keytable-generated-from-spark-dataframe/310/2 "2017-10-08T15:55:05Z")

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Running `kt = kt.annotate('v = Variant(v)').key_by('v')` beforehand should do the trick

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**Author:** ![jerryliu2005](https://yyz2.discourse-cdn.com/flex036/user_avatar/discuss.hail.is/jerryliu2005/32/97_2.png) [@jerryliu2005](https://discuss.hail.is/u/jerryliu2005)\
**Post date:** [October 8, 2017, 4:46pm UTC](https://discuss.hail.is/t/annotate-variants-table-using-keytable-generated-from-spark-dataframe/310/3 "2017-10-08T16:46:01Z")

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Thanks very much, @konradjk!  
The Hail community is awesome! 👍