Importing Multiple Files¶

The importFolder (R)/import_file (Python) function can be used to import multiple local 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.
When parsing a data file containing timestamps that do not include a timezone, the timestamps will be interpreted as UTC (GMT). You can override the parsing timezone using the following:
- R: h2o.setTimezone("America/Los Angeles")
- Python: h2o.cluster().timezone = "America/Los Angeles"
The examples below assumes that the H2O-3 GitHub repository has been cloned, and that the following command was run in the h2o-3 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 .csv files from an anomaly folder stored locally
ecgPath <- "../path_to_h2o-3/smalldata/anomaly/"
ecg_pattern.hex <- h2o.importFolder(path=ecgPath,
                                    pattern = ".*.csv",
                                    destination_frame = "ecg_pattern.hex")

class(ecg_pattern.hex)
summary(ecg_pattern.hex)

# To import all .csv files from an anomaly folder stored locally matching the regex ".*\.csv"
import h2o
h2o.init()
ecg_pattern = h2o.import_file(path="../path_to_h2o-3/smalldata/anomaly/",pattern = ".*\.csv")