Markdown display

[yakir12]

It would be useful if writetable had an option to save the table as a markdown table (the repl output seems to already be in markdown).

[ExpandingMan]

+1 for this, or, better yet, a LaTeX tabular. I think I/O functionality either has been or will be moved to another package though, so I'm not sure whether this is still the appropriate place for issues like this.

[nalimilan]

writetable is meant to write CSV files, and it's going to be deprecated in favor of CSV.jl anyway. Markdown output should rather go through the show machinery, just like we currently do for HTML and LaTeX (in DataTables only, see this file).

[ExpandingMan]

I wasn't aware the LaTeX output functionality existed, that is very cool indeed!

[quinnj]

It would actually be pretty easy to write a MarkdownTables.jl package that implemented the DataStreams interface. Then you read/write a markdown table from any other DataStream package.

[yakir12]

I agree that this functionality doesn't need to live in DataFrames. Markdown.jl lives in Base, and therefore it should be slim (right?), but there could be many other functionalities that become relevant for such a package. I'm mainly thinking of use-cases involving pandoc, where you'd parse some data you have in julia (e.g. as a DataFrame) to markdown, and then use pandoc to convert that into whatever you want (LaTeX, HTML, etc).

[korsbo]

It is possible to generate both markdown and LaTeX tables from a DataFrame using Latexify.jl. If you feel that Latexify is not doing a sufficiently good job of this, then feel free to post an issue there (or submit a PR).

[bkamins]

I think this should be a generic functionality for any type that supports Tables.jl API so it is probably outside DataFrames.jl so I am closing this (feel free to reopen if you think we should discuss it more here).

[nalimilan]

Given that the code for that should be pretty simple (basically like CSV), it wouldn't be absurd to support that in DataFrames.jl if somebody wants to make a PR. If we want to put this in a separate package, better have a single package taking any table in the Tables.jl sense and supporting a variety of MIME types. Then DataFrames could use it to implement show(io, mime, df).

[pgagarinov]

@bkamins

Documentation for show says:

However, passing tf=tf_format into show doesn't seem to work:

And I have to call pretty_table directly to make it work:

Is ignoring tf kwarg the expected behavior?

[bkamins]

@ronisbr - could you please comment here? Maybe we need to update the docstring? Thank you!

[bkamins]

Also here is what I get:

julia> using DataFrames

julia> show(DataFrame(a=1:3,b='x':'z'), tf=PrettyTables.tf_markdown)
3×2 DataFrame
 Row | a      b    
     | Int64  Char 
-----|-------------
   1 |     1  x
   2 |     2  y
   3 |     3  z
julia> PrettyTables.pretty_table(DataFrame(a=1:3,b='x':'z'), tf=PrettyTables.tf_markdown)
|     a |    b |
| Int64 | Char |
|-------|------|
|     1 |    x |
|     2 |    y |
|     3 |    z |

(and maybe this is what is expected?)

[ronisbr]

It is doing what it is supposed to. The problem is that the other configurations in DataFrames hide vertical lines. Hence, in this case, you will also need to pass vlines = :all.

[bkamins]

Thank you (this is what I assumed, but unfortunately I have not mastered all options of PrettyTables.jl yet)

[ronisbr]

No problem! Feel free to ping me in every issue related to PrettyTables.