如何对一个DataFrameRow使用map

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1

这里有一个temp::DataFrameRow

2020-06-19 16-37-04 的屏幕截图
2020-06-19 16-37-04 的屏幕截图929×214 19.9 KB

我要做的是统计temp中missing的个数，那么我应该这么写
length(filter(ismissing,temp)),但这个会报错，先不管他，给你们看看这里怪在哪里

# 1.
julia> ismissing(temp[1])
true

# 2.
julia> map(ismissing,temp)
(color = true,
 director_name = false,
 num_critic_for_reviews = true,
 duration = true,
 director_facebook_likes = false,)

# 3.
julia> [ismissing(i) for i in temp]
5-element Array{Bool,1}:
 1
 0
 1
 1
 0

# 4.
julia> filter(ismissing,temp)
ERROR: MethodError: no method matching filter(::typeof(ismissing), ::DataFrameRow{DataFrame,DataFrames.Index})
Closest candidates are:
  filter(::Function, ::DataStructures.LinkedList{T}) where T at /home/steiner/.julia/packages/DataStructures/GvsTk/src/list.jl:82
  filter(::Function, ::DataStructures.MutableLinkedList{T}) where T at /home/steiner/.julia/packages/DataStructures/GvsTk/src/mutable_list.jl:93
  filter(::Any, ::Tuple{Any,Any,Any,Any,Any,Any,Any,Any,Any,Any,Any,Any,Any,Any,Any,Any,Vararg{Any,N}} where N) at tuple.jl:267
  ...
Stacktrace:
 [1] top-level scope at REPL[131]:1

image
有没有人告诉我应该怎么做啊

2

filter针对DataFrame的每一行，给出一个布尔值并提取出为true的行，所以应该是无法完成对每个元素判断的操作

3

所以
sum(ismissing.(Matrix(a)))

4

好像不对啊

julia> Matrix(temp)
ERROR: MethodError: no method matching Array{T,2} where T(::DataFrameRow{DataFrame,DataFrames.Index})
Closest candidates are:
  Array{T,2} where T(::LinearAlgebra.SymTridiagonal{T,V} where V<:AbstractArray{T,1}) where T at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/LinearAlgebra/src/tridiag.jl:110
  Array{T,2} where T(::LinearAlgebra.Tridiagonal{T,V} where V<:AbstractArray{T,1) where T at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/LinearAlgebra/src/tridiag.jl:527
  Array{T,2} where T(::LinearAlgebra.LowerTriangular{T,S} where S<:AbstractArray{T,2}) where T at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.4/LinearAlgebra/src/triangular.jl:34
  ...
Stacktrace:
 [1] top-level scope at REPL[137]:1
5

sum(map(ismissing,temp))

6

这个可以运行，看来我还是不怎么熟悉命名元组