# How to use Pkg.dependencies() instead of Pkg.installed()

**URL:** <https://discourse.julialang.org/t/how-to-use-pkg-dependencies-instead-of-pkg-installed/36416>\
**Category:** General Usage\
**Tags:** package, package-manager\
**Created:** [March 24, 2020, 5:11am UTC](https://discourse.julialang.org/t/how-to-use-pkg-dependencies-instead-of-pkg-installed/36416 "2020-03-24T05:11:54Z")\
**Posts on this page:** 2\
**Page:** 2

<div class="post-metadata">

**Author:** ![Ralf\_Dietrich](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ralf_dietrich/32/5643_2.png) [@Ralf\_Dietrich](https://discourse.julialang.org/u/Ralf_Dietrich)\
**Post date:** [July 9, 2023, 6:17pm UTC](https://discourse.julialang.org/t/how-to-use-pkg-dependencies-instead-of-pkg-installed/36416/21 "2023-07-09T18:17:15Z")

</div>

Since my last post, I’ve made a few more improvements to the code

```julia
input_prompt() = splitpath(Base.active_project())[end-1] * " > "

atreplinit() do repl
    repl.options.iocontext[:compact] = false # Display all Digits
    #colorscheme!("GitHubDarkDimmed") # Optional
    OhMyREPL.input_prompt!(input_prompt, :magenta)
end

if !isfile("Project.toml")
    # Make sure all needed Pkg's are ready to go in standard Environment. Don't touch it in a Package
    neededPackages = [:Revise, :OhMyREPL, :BenchmarkTools, :IJulia, :Documenter] 
    using Pkg;
    for neededPackage in neededPackages
        (String(neededPackage) in keys(Pkg.project().dependencies)) || Pkg.add(String(neededPackage))
        @eval using $neededPackage
    end
end

using OhMyREPL

```

---

<div class="post-metadata">

**Author:** ![TheLateKronos](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/thelatekronos/32/12824_2.png) [@TheLateKronos](https://discourse.julialang.org/u/TheLateKronos)\
**Post date:** [November 9, 2023, 8:35am UTC](https://discourse.julialang.org/t/how-to-use-pkg-dependencies-instead-of-pkg-installed/36416/22 "2023-11-09T08:35:54Z")

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I just want to add an alternative approach. It bases itself on the function `Base.identify_package`, which can be used to get the UUID of a package based on its name:

```julia
julia> using Pkg

julia> haskey(Pkg.dependencies(), Base.identify_package("Revise").uuid)
true

```

There are two caveats. The first is that the docstring of `Pkg.dependencies` states that “This feature is considered experimental.”, so I am not 100% sure that this is what things will look like forever. But given the stability of Pkg, I am certain that this will work for a long time.

The second is that if the package does not exist, `Base.identify_package` returns `nothing`, meaning that when we try to get the field `uuid`, we get an error:

```julia
julia> haskey(Pkg.dependencies(), Base.identify_package("NotAPackage").uuid)
ERROR: type Nothing has no field uuid
Stacktrace:
 [1] getproperty(x::Nothing, f::Symbol)
   @ Base ./Base.jl:37
 [2] top-level scope
   @ REPL[10]:1

```

A complete solution would therefore require the rather verbose

```julia
julia> haskey(Pkg.dependencies(), Base.identify_package("NotAPackage")===nothing ? nothing : Base.identify_package("NotAPackage").uuid)
false

```

So I guess something like `haskey(Pkg.project().dependencies, "Revise")`, posted previously, is actually more robust and shorter.

[Previous page](https://discourse.julialang.org/t/how-to-use-pkg-dependencies-instead-of-pkg-installed/36416.md?page=1)