Importing Multiple Files¶

The importFolder (R)/import_file (Python) function can be used to import multiple files by specifying a directory and a pattern. Example patterns include:

pattern="/A/.*/iris_.*": Import all files that have the pattern /A/.*/iris_.* in the specified directory.
pattern="/A/iris_.*": Import all files that have the pattern /A/iris_.* in the specified directory.
pattern="/A/B/iris_.*": Import all files that have the pattern /A/B/iris_.* in the specified directory.
pattern="iris_.*": Import all files that have the pattern iris_.* in the specified directory.

Notes:

All files that are specified to be included must have the same number and set of columns.
The Python example below assumes that the H2O-3 GitHub repository has been cloned, and that the following command was run in the h2o folder to retrieve the smalldata datasets.
```
./gradlew syncSmalldata
```

# To import all .csv files from the prostate_folder directory:
> library(h2o)
> h2o.init()
> prosPath <- system.file("extdata", "prostate_folder", package = "h2o")
> prostate_pattern.hex <- h2o.importFolder(path = prosPath, pattern = ".*.csv", destination_frame = "prostate.hex")
> class(prostate_pattern.hex)
> summary(prostate_pattern.hex)

# To import all files in the iris folder matching the regex "iris_.*\.csv"
>>> import h2o
>>> h2o.init()
>>> iris_pattern = h2o.import_file(path = "../smalldata/iris",pattern = "iris_.*\.csv")