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  • R语言nest_join()函数

    nest_join() returns all rows and columns in x with a new nested-df column that contains all matches from y. When there is no match, the list column is a 0-row tibble.

    nest_join()类似left_join(),返回的形式不一样。

    band_members %>% nest_join(band_instruments)
    #> Joining, by = "name"
    #> # A tibble: 3 x 3
    #>   name  band    band_instruments
    #>   <chr> <chr>   <list>          
    #> 1 Mick  Stones  <tibble [0 × 1]>
    #> 2 John  Beatles <tibble [1 × 1]>
    #> 3 Paul  Beatles <tibble [1 × 1]>
    

    nest_join之后,band_instruments的结果打印出来

    [[1]]
    # A tibble: 0 x 1
    # … with 1 variable: plays <chr>
    
    [[2]]
    # A tibble: 1 x 1
      plays 
      <chr> 
    1 guitar
    
    [[3]]
    # A tibble: 1 x 1
      plays
      <chr>
    1 bass 
    

    对比left_join

    > band_members %>% left_join(band_instruments)
    Joining, by = "name"
    # A tibble: 3 x 3
      name  band    plays 
      <chr> <chr>   <chr> 
    1 Mick  Stones  NA    
    2 John  Beatles guitar
    3 Paul  Beatles bass 
    
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  • 原文地址:https://www.cnblogs.com/yaos/p/14014131.html
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