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https://github.com/tototoshi/scala-csv
CSV Reader/Writer for Scala
https://github.com/tototoshi/scala-csv
Last synced: 9 days ago
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CSV Reader/Writer for Scala
- Host: GitHub
- URL: https://github.com/tototoshi/scala-csv
- Owner: tototoshi
- License: other
- Created: 2012-03-08T17:02:19.000Z (over 12 years ago)
- Default Branch: master
- Last Pushed: 2024-10-29T23:51:26.000Z (10 days ago)
- Last Synced: 2024-10-30T01:54:39.336Z (10 days ago)
- Language: Scala
- Homepage:
- Size: 5.91 MB
- Stars: 697
- Watchers: 29
- Forks: 141
- Open Issues: 30
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
- Codeowners: .github/CODEOWNERS
Awesome Lists containing this project
- awesome-scala - **scala-csv** - csv)  (Table of Contents / CSV)
README
# scala-csv
## build.sbt
```scala
libraryDependencies += "com.github.tototoshi" %% "scala-csv" % "2.0.0"
```
## Example
### import
```scala
scala> import com.github.tototoshi.csv._
```
### Reading example
sample.csv
```
a,b,c
d,e,f
```
You can create CSVReader instance with CSVReader#open.
```scala
scala> val reader = CSVReader.open(new File("sample.csv"))
```
#### Reading all lines
```scala
scala> val reader = CSVReader.open(new File("sample.csv"))
reader: com.github.tototoshi.csv.CSVReader = com.github.tototoshi.csv.CSVReader@36d0c6dd
scala> reader.all()
res0: List[List[String]] = List(List(a, b, c), List(d, e, f))
scala> reader.close()
```
#### Using iterator
```scala
scala> val reader = CSVReader.open("sample.csv")
reader: com.github.tototoshi.csv.CSVReader = com.github.tototoshi.csv.CSVReader@22d568da
scala> val it = reader.iterator
it: Iterator[Seq[String]] = non-empty iterator
scala> it.next
res0: Seq[String] = List(a, b, c)
scala> it.next
res1: Seq[String] = List(d, e, f)
scala> it.next
java.util.NoSuchElementException: next on empty iterator
at com.github.tototoshi.csv.CSVReader$$anon$1$$anonfun$next$1.apply(CSVReader.scala:55)
at com.github.tototoshi.csv.CSVReader$$anon$1$$anonfun$next$1.apply(CSVReader.scala:55)
at scala.Option.getOrElse(Option.scala:108)
scala> reader.close()
```
#### Reading all lines as Stream
```scala
scala> val reader = CSVReader.open(new File("sample.csv"))
reader: com.github.tototoshi.csv.CSVReader = com.github.tototoshi.csv.CSVReader@7dae76b4
scala> reader.toStream
res7: Stream[List[String]] = Stream(List(a, b, c), ?)
```
#### Reading one line at a time
There a two ways available. #foreach and #readNext.
```scala
scala> val reader = CSVReader.open(new File("sample.csv"))
reader: com.github.tototoshi.csv.CSVReader = com.github.tototoshi.csv.CSVReader@4720a918
scala> reader.foreach(fields => println(fields))
List(a, b, c)
List(d, e, f)
scala> reader.close()
```
```scala
scala> val reader = CSVReader.open(new File("sample.csv"))
reader: com.github.tototoshi.csv.CSVReader = com.github.tototoshi.csv.CSVReader@4b545701
scala> reader.readNext()
res3: Option[List[String]] = Some(List(a, b, c))
scala> reader.readNext()
res4: Option[List[String]] = Some(List(d, e, f))
scala> reader.readNext()
res5: Option[List[String]] = None
scala> reader.close()
```
#### Reading a csv file with column headers
with-headers.csv
```
Foo,Bar,Baz
a,b,c
d,e,f
```
````scala
scala> val reader = CSVReader.open(new File("with-headers.csv"))
reader: com.github.tototoshi.csv.CSVReader = com.github.tototoshi.csv.CSVReader@1a64e307
scala> reader.allWithHeaders()
res0: List[Map[String,String]] = List(Map(Foo -> a, Bar -> b, Baz -> c), Map(Foo -> d, Bar -> e, Baz -> f))
````
### Writing example
#### Writing all lines with #writeAll
```scala
scala> val f = new File("out.csv")
scala> val writer = CSVWriter.open(f)
writer: com.github.tototoshi.csv.CSVWriter = com.github.tototoshi.csv.CSVWriter@783f77f1
scala> writer.writeAll(List(List("a", "b", "c"), List("d", "e", "f")))
scala> writer.close()
```
#### Writing one line at a time with #writeRow
```scala
scala> val f = new File("out.csv")
scala> val writer = CSVWriter.open(f)
writer: com.github.tototoshi.csv.CSVWriter = com.github.tototoshi.csv.CSVWriter@41ad4de1
scala> writer.writeRow(List("a", "b", "c"))
scala> writer.writeRow(List("d", "e", "f"))
scala> writer.close()
```
#### Appending lines to the file that already exists
The default behavior of CSVWriter#open is overwriting.
To append lines to the file that already exists, Set the append flag true.
```scala
scala> val writer = CSVWriter.open("a.csv", append = true)
writer: com.github.tototoshi.csv.CSVWriter = com.github.tototoshi.csv.CSVWriter@67a84246
scala> writer.writeRow(List("4", "5", "6"))
scala> writer.close()
```
### Customizing the format
CSVReader/Writer#open takes CSVFormat implicitly.
Define your own CSVFormat when you want to change the CSV's format.
```scala
scala> :paste
// Entering paste mode (ctrl-D to finish)
implicit object MyFormat extends DefaultCSVFormat {
override val delimiter = '#'
}
val w = CSVWriter.open(new java.io.OutputStreamWriter(System.out))
// Exiting paste mode, now interpreting.
defined module MyFormat
w: com.github.tototoshi.csv.CSVWriter = com.github.tototoshi.csv.CSVWriter@6cd66afa
scala> w.writeRow(List(1, 2, 3))
"1"#"2"#"3"
```
### Changing the encoding
By default the UTF-8 is set. To change it, for example, to ISO-8859-1 you can set it in the CSVReader:
```scala
scala> val reader = CSVReader.open(filepath, "ISO-8859-1")
reader: com.github.tototoshi.csv.CSVReader = com.github.tototoshi.csv.CSVReader@6bcb69ba
```
## Dev
```
$ git clone https://github.com/tototoshi/scala-csv.git
$ cd scala-csv
$ sbt
> test
```
## License
[Apache 2.0](http://www.apache.org/licenses/LICENSE-2.0)