# Julia program reading CSV file from stdin
**URL:** https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208
**Category:** Data
**Created:** [August 28, 2018, 8:06pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208 "2018-08-28T20:06:50Z")
**Posts on this page:** 14
**Page:** 1
### Author:  [@iwelch](https://discourse.julialang.org/u/iwelch)
#### Post date: [August 28, 2018, 8:06pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/1 "2018-08-28T20:06:50Z")
I am wondering whether it is possible to embed a CSV file in a julia program. It almost works with `CSV.read()`, except I do not see a way to signal “EOF” (like with ^D on the REPL).
```julia
julia> using DataFrames, CSV
julia> d= CSV.read( stdin )
yyyymmdd,days,rate
19960102,9,5.763067
19960102,15,5.745902
19960103,8,5.763067
19960103,14,5.747397
^D ## please no unprintable control characters
```
any suggestions?
---
### Author:  [@Iagoba\_Apellaniz](https://discourse.julialang.org/u/Iagoba_Apellaniz)
#### Post date: [August 28, 2018, 8:13pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/2 "2018-08-28T20:13:49Z")
Have you tried using the `head` function from DataFrames? See [Loading a Classic Data Set](https://juliadata.github.io/DataFrames.jl/stable/man/getting_started.html#Loading-a-Classic-Data-Set-1)
---
### Author:  [@iwelch](https://discourse.julialang.org/u/iwelch)
#### Post date: [August 28, 2018, 8:23pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/3 "2018-08-28T20:23:12Z")
I think `head` shortens output, and does little with input.
---
### Author:  [@quinnj](https://discourse.julialang.org/u/quinnj)
#### Post date: [August 28, 2018, 10:36pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/4 "2018-08-28T22:36:02Z")
Hmmm…I’m not quite clear on the question here; is it really to read a CSV file from `stdin` or do you just want to “hard-code” a csv file in a script? For the latter, you could do something as simple as:
```julia
csv = CSV.read(IOBuffer("""
col1,col2
1,2
3,4
"""))
```
For the former, I think you’re right in I’m not sure how you would signal EOF so CSV knows to stop reading (at least in a non-blocking way).
---
### Author:  [@iwelch](https://discourse.julialang.org/u/iwelch)
#### Post date: [August 28, 2018, 10:56pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/5 "2018-08-28T22:56:33Z")
this is a pretty nice alternative, although I still would prefer my version.
PS: I am going to file a suggestion for a “endat=” keyword.
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [August 29, 2018, 8:51am UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/6 "2018-08-29T08:51:52Z")
> [@iwelch](#):
>
> I am wondering whether it is possible to embed a CSV file in a julia program.
This is not an answer to your original question, but if I wanted to include nontrivial data in a package/project, I would just `Serialization.serialize`, and read it at runtime from a path I determined with `@ __DIR__ `.
---
### Author:  [@iwelch](https://discourse.julialang.org/u/iwelch)
#### Post date: [August 29, 2018, 4:10pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/7 "2018-08-29T16:10:43Z")
agreed. the principal use of **END** would be for small data frames, such as illustrative data sets.
perl also has an useful **DATA** feature that one can stick at the end of illustrative programs. but this is not a package feature that would be easy to implement. then again, perl is not so very good dealing with multiple files packaged together and residing elsewhere for its quick-and-dirty uses.
regards,
/iaw
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [August 29, 2018, 4:16pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/8 "2018-08-29T16:16:52Z")
> [@iwelch](#):
>
> small data frames, such as illustrative data sets.
When small, why not just have it in the source directly evaluated, possibly in a file that is included? Eg
```julia
const example_data = DataFrame(a = ..., b = ...)
```
with appropriate linebreaks etc if applicable.
---
### Author:  [@iwelch](https://discourse.julialang.org/u/iwelch)
#### Post date: [August 29, 2018, 4:29pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/9 "2018-08-29T16:29:44Z")
definitely not as good visually for the reader. see, our illustrative finance data sets are often not calculated, but real data (think interest rates and stock returns in different months), and can be up to, say, 24 months long. just aligning them this way is a pain.
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [August 29, 2018, 5:06pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/10 "2018-08-29T17:06:49Z")
The CSV you display in the opening post is not aligned either.
I am now not really sure what you want. For small datasets, you can just use code and align (and comment!) as you prefer. For larger datasets, this is presumably not a concern as they would not be eyeballed directly.
Perhaps you can also include an IJulia notebook that visualizes certain features of the data (eg distribution, lag-1 scatter plot).
---
### Author:  [@yuyichao](https://discourse.julialang.org/u/yuyichao)
#### Post date: [August 29, 2018, 5:38pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/11 "2018-08-29T17:38:37Z")
A `END` keyword won’t work as what you suggested since the script is **NOT** read through STDIN. You’ll never be able to read anything. What you are asking for is just a way to embed string in a script and I don’t see what’s missing from a normal multi-line string constant as @quinnj suggests.
---
### Author:  [@iwelch](https://discourse.julialang.org/u/iwelch)
#### Post date: [August 29, 2018, 6:18pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/12 "2018-08-29T18:18:15Z")
thx, yuyichao. if the script itself is not going through stdin, then this is moot…unless it is possible to designate the input stream.
tamas—think about
```julia
julia> using DataFrames, CSV
julia> d= CSV.read( scriptstream )
yyyymmdd xmkt rf
1 20121227 -0.11 -0.19
2 20121228 -1.00 -0.03
3 20121231 1.71 -0.04
4 20130102 2.62 0.30
5 20130103 -0.14 0.11
6 20130104 0.55 0.48
7 20130107 -0.31 -0.42
8 20130108 -0.26 0.02
9 20130109 0.34 -0.40
10 20130110 0.66 0.45
11 20130111 0.02 -0.38
12 20130114 -0.06 0.00
__END__
julia> ## do many different types of data analysis.
```
the `"""` construct is a reasonable alternative. not as nice, but close enough. the listing data on long lines as in `DataFrame( yyyymmdd= ..., ...)` is also feasible, but again not as nice for this purpose.
---
### Author:  [@yuyichao](https://discourse.julialang.org/u/yuyichao)
#### Post date: [August 29, 2018, 6:37pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/13 "2018-08-29T18:37:17Z")
Still, are you talking about typing in data in a REPL or embeding data in a script. You always talk about script and then give REPL as example.
> [@iwelch](#):
>
> the `"""` construct is a reasonable alternative. not as nice, but close enough.
What I don’t understand is what’s not nice about it, or really, what are you looking for. AFAICT it’s just the difference between
```julia
d = read()
__END__
```
and
```julia
str = """
""" # __END__
d = read(IOBuffer(str))
```
That’s roughly the same number of lines. You get your ` __END__ ` in the comment if you want. Syntax highlight already works. `read` comes after the data but if you really want you can create a string macro and do
```julia
data = csv"""
"""
```
if it hasn’t been done already. (Should be as simple as `macro csv_str(str) :(read(IOBuffer($(esc(str))))) end`)
> [@iwelch](#):
>
> CSV.read( scriptstream )
This still won’t work. You’ll still need to convience the parser to ignore your data, which is almost certainly invalid code.
---
### Author:  [@iwelch](https://discourse.julialang.org/u/iwelch)
#### Post date: [August 29, 2018, 7:56pm UTC](https://discourse.julialang.org/t/julia-program-reading-csv-file-from-stdin/14208/14 "2018-08-29T19:56:56Z")
on reflection, I think you are right.