# Launching examples from a Julia package
**URL:** https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814
**Category:** General Usage
**Tags:** question, jupyter
**Created:** [July 12, 2017, 4:35pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814 "2017-07-12T16:35:22Z")
**Posts on this page:** 18
**Page:** 1
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 12, 2017, 4:35pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/1 "2017-07-12T16:35:22Z")
I am trying to provide a convenience function for the users of my package that launchs Jupyter notebook examples from the command line without depending on IJulia:
```julia
module Foo
# ...
function examples()
using IJulia
notebook(dir=joinpath(@ __DIR__ ,"examples"))
end
end
```
The user would then launch the examples with “Foo.examples()” from the Julia prompt. The code above doesn’t work because we are not allowed to have `using` statements inside of functions. Is there any solution around this?
I believe that we would benefit from having reproducible examples in Julia packages via a standardized process. Is there anything happening with this regards already?
---
### Author:  [@mauro3](https://discourse.julialang.org/u/mauro3)
#### Post date: [July 12, 2017, 4:50pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/2 "2017-07-12T16:50:01Z")
You could use eval: `@eval using IJulia`.
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 12, 2017, 5:02pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/3 "2017-07-12T17:02:14Z")
Thank you @mauro3. I am getting a strange error message now saying that `notebook()` is not a valid method:
```julia
ERROR: MethodError: no method matching notebook()
The applicable method may be too new: running in world age 21816, while current world is 21820.
Closest candidates are:
notebook(; dir, detached) at /home/juliohm/.julia/v0.6/IJulia/src/IJulia.jl:104 (method too new to be called from this world context.)
```
---
### Author:  [@mauro3](https://discourse.julialang.org/u/mauro3)
#### Post date: [July 12, 2017, 5:17pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/4 "2017-07-12T17:17:42Z")
Yep. Maybe use `invokelatest` or also `@eval`.
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 12, 2017, 5:22pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/5 "2017-07-12T17:22:03Z")
Perfect @mauro3, the final solution for future reference:
```julia
module Foo
function examples()
@eval using IJulia
@eval notebook(dir=Pkg.dir("Foo","examples"))
end
end
```
---
### Author:  [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)
#### Post date: [July 12, 2017, 9:31pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/6 "2017-07-12T21:31:10Z")
> [@juliohm](#):
>
> joinpath(Pkg.dir(“Foo”),“examples”)
Pkg.dir has a built in joinpath, so this can be elegantly written as
`Pkg.dir("Foo", "examples")`
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 12, 2017, 9:32pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/7 "2017-07-12T21:32:35Z")
Thanks @baggepinnen, that is definitely more elegant 🙂
Will update the answer and mark as solved.
---
### Author:  [@tkelman](https://discourse.julialang.org/u/tkelman)
#### Post date: [July 13, 2017, 12:38pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/8 "2017-07-13T12:38:45Z")
The `@ __DIR__ ` you originally had is better than using `Pkg.dir`, as the former will work if the package is loaded from somewhere else on `LOAD_PATH`.
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 13, 2017, 2:51pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/9 "2017-07-13T14:51:33Z")
Thank you @tkelman, I will unroll the changes and use `@ __DIR__ ` again, I always forget that `Pkg.dir()` is not portable.
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 13, 2017, 2:54pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/10 "2017-07-13T14:54:35Z")
@tkelman, actually `@ __DIR__ ` isn’t defined in the REPL? I tried calling the function after loading the package, and `@ __DIR__ ` is `nothing`.
---
### Author:  [@tkelman](https://discourse.julialang.org/u/tkelman)
#### Post date: [July 13, 2017, 3:01pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/11 "2017-07-13T15:01:46Z")
Yeah depends whether you intend to write the code down in a .jl file that users will include, or as an example that they will copy-paste in the REPL. I think `@ __DIR__ ` was changed recently to behave as `pwd()` when used in the REPL, but that’s not exactly what you want for copy-pasted code.
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 13, 2017, 3:08pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/12 "2017-07-13T15:08:31Z")
In that case, I will keep using `Pkg.dir()`, it should work in nearly 100% of the cases.
---
### Author:  [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)
#### Post date: [July 13, 2017, 4:53pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/13 "2017-07-13T16:53:49Z")
Why not
```julia
module Foo
using IJulia
function examples()
notebook(dir=Pkg.dir("Foo","examples"))
end
end
```
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 13, 2017, 5:13pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/14 "2017-07-13T17:13:22Z")
@PetrKryslUCSD, I don’t want to depend on IJulia, that is why we delay the evaluation inside of the function. So everyone that needs to run the examples, will install IJulia.
---
### Author:  [@Evizero](https://discourse.julialang.org/u/Evizero)
#### Post date: [July 13, 2017, 5:21pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/15 "2017-07-13T17:21:22Z")
> [@juliohm](#):
>
> module Foo
> function examples()
> @eval using IJulia
> @eval notebook(dir=Pkg.dir(“Foo”,“examples”))
> end
> end
> [@juliohm](#):
>
> actually @ **DIR** isn’t defined in the REPL
Untried, but maybe that is avoidable by extracting the macro out of the `@eval` portion
```julia
module Foo
function examples()
path = joinpath(@ __DIR__ , "examples")
@eval using IJulia
@eval notebook(dir=path))
end
end
```
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 13, 2017, 5:29pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/16 "2017-07-13T17:29:26Z")
Thank you @Evizero, unfortunately it doesn’t work, it says `path` is undefined?
---
### Author:  [@adamslc](https://discourse.julialang.org/u/adamslc)
#### Post date: [July 13, 2017, 5:53pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/17 "2017-07-13T17:53:27Z")
Maybe try
```julia
@eval notebook(dir=$path)
```
---
### Author:  [@juliohm](https://discourse.julialang.org/u/juliohm)
#### Post date: [July 13, 2017, 6:08pm UTC](https://discourse.julialang.org/t/launching-examples-from-a-julia-package/4814/18 "2017-07-13T18:08:00Z")
There are currently two possible solutions thanks to @mauro3, @Evizero, @adamslc and @tkelman:
Solution a)
```julia
function examples()
@eval using IJulia
opennotebook(dir) = notebook(dir=dir)
Base.invokelatest(opennotebook, joinpath(@ __DIR__ ,"..","examples"))
end
```
Solution b)
```julia
function examples()
path = joinpath(@ __DIR__ ,"..","examples")
@eval using IJulia
@eval notebook(dir=$path)
end
```
I am biased towards solution b), will update the answer in the thread.