无法在 Julia 1.0 中安装“DateTime”包？

Question

无法在 Julia 1.0 中添加“DateTime”包。如何对这个问题进行排序？？使用包

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> 

Answer 1

文档DateTime.jl如下：

这个项目现在已经过时了。从 0.4-dev 版本开始，日期和时间功能已添加到 Julia 基础中。

您需要什么功能？通常，在使用 date 时使用内置Dates包

using Dates

编辑

由于您在这里要求提供示例，因此它是：

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 ?

请注意点运算符如何.用于矢量化操作。