无法在Julia 1.0中添加“ DateTime”包。如何对这个问题进行排序? 使用Pkg
julia> Pkg.add("DateTime")
ERROR: The following package names could not be resolved:
* dateTime (not found in project, manifest or registry)
Please specify by known `name=uuid`.
Stacktrace:
[1] pkgerror(::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Types.jl:120
[2] #ensure_resolved#72(::Bool, ::Function, ::Pkg.Types.EnvCache, ::Array{Pkg.Types.PackageSpec,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Types.jl:1010
[3] #ensure_resolved at ./none:0 [inlined]
[4] #add_or_develop#15(::Symbol, ::Bool, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:49
[5] #add_or_develop at ./none:0 [inlined]
[6] #add_or_develop#14 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:31 [inlined]
[7] #add_or_develop at ./none:0 [inlined]
[8] #add_or_develop#13 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:29 [inlined]
[9] #add_or_develop at ./none:0 [inlined]
[10] #add_or_develop#12(::Base.Iterators.Pairs{Symbol,Symbol,Tuple{Symbol},NamedTuple{(:mode,),Tuple{Symbol}}}, ::Function, ::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:28
[11] #add_or_develop at ./none:0 [inlined]
[12] #add#20 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:59 [inlined]
[13] add(::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:59
[14] top-level scope at none:0
julia>
答案 0 :(得分:3)
DateTime.jl
的文档显示为:
该项目现在已过时。从0.4-dev版本开始,日期和 时间功能已添加到Julia库。
您需要什么功能?通常,在处理日期时,请使用内置的Dates
包
using Dates
由于您在这里要求的示例是:
julia> using DataFrames
julia> d = DataFrame( col1 = ["2018-01-01","2018-02-10","2018-03-20"])
3×1 DataFrame
│ Row │ col1 │
│ │ String │
├─────┼────────────┤
│ 1 │ 2018-01-01 │
│ 2 │ 2018-02-10 │
│ 3 │ 2018-03-20 │
julia> using Dates
julia> d.col1 = Date.(d.col1);
julia> d
3×1 DataFrame
│ Row │ col1 │
│ │ Date │
├─────┼────────────┤
│ 1 │ 2018-01-01 │
│ 2 │ 2018-02-10 │
│ 3 │ 2018-03-20 │
请注意如何使用点运算符.
对操作进行矢量化。