dataframe-parquet 1.3.0.0 → 1.4.0.0

raw patch · 2 files changed

+65/−11 lines, 2 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• dataframe-parquet.cabal +1/−1
• src/DataFrame/Typed/IO/Parquet.hs +64/−10

@@ -1,6 +1,6 @@ cabal-version:      3.4 name:               dataframe-parquet-version:            1.3.0.0+version:            1.4.0.0  synopsis:           Parquet reader and writer for the dataframe ecosystem. description:

@@ -1,3 +1,4 @@+{-# LANGUAGE AllowAmbiguousTypes #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE TypeApplications #-} @@ -23,35 +24,88 @@     readParquetFiles, ) where +import Control.Applicative ((<|>))+import Control.Exception (SomeException, try) import qualified Data.Text as T -import DataFrame.IO.Parquet (ParquetReadOptions)+import DataFrame.IO.Parquet (ParquetReadOptions (..), defaultParquetReadOptions) import qualified DataFrame.IO.Parquet as Parquet import DataFrame.Typed.Freeze (freezeOrThrow, freezeWithError)-import DataFrame.Typed.Schema (KnownSchema)+import DataFrame.Typed.Schema (KnownSchema, schemaColumnNames) import DataFrame.Typed.Types (TypedDataFrame) --- | Read a Parquet file into a typed DataFrame, throwing on schema mismatch.+{- | Read only the columns @cols@ names, unless the caller selected columns+themselves. Parquet supplies the element types, so the schema contributes the+projection and the freeze checks the types.+-}+schemaOptions ::+    forall cols. (KnownSchema cols) => ParquetReadOptions -> ParquetReadOptions+schemaOptions opts =+    opts+        { selectedColumns = selectedColumns opts <|> Just (schemaColumnNames @cols)+        }++{- | Read a Parquet file into a typed DataFrame, throwing on schema mismatch.+Reads only the columns @cols@ names.++==== __Example__+@+ghci> trips <- readParquet \@Trips \"trips.parquet\"+@+-} readParquet ::     forall cols. (KnownSchema cols) => FilePath -> IO (TypedDataFrame cols)-readParquet path = Parquet.readParquet path >>= freezeOrThrow @cols+readParquet = readParquetWithOpts @cols defaultParquetReadOptions --- | Read a Parquet file, returning a descriptive error on schema mismatch.+{- | Read a Parquet file, returning a descriptive error on schema mismatch or+a missing column instead of throwing.++==== __Example__+@+ghci> readParquetWithError \@Trips \"trips.parquet\"+Right (TDF ...)+@+-} readParquetWithError ::     forall cols.     (KnownSchema cols) =>     FilePath -> IO (Either T.Text (TypedDataFrame cols))-readParquetWithError path = freezeWithError <$> Parquet.readParquet path+readParquetWithError path = do+    r <-+        try+            (Parquet.readParquetWithOpts (schemaOptions @cols defaultParquetReadOptions) path)+    pure $ case r of+        Left (e :: SomeException) -> Left (T.pack (show e))+        Right df -> freezeWithError df --- | Read a Parquet file with custom options, throwing on schema mismatch.+{- | Read a Parquet file with custom options, throwing on schema mismatch. The+schema still supplies the column selection; an explicit 'selectedColumns'+takes precedence.++==== __Example__+@+ghci> trips <- readParquetWithOpts \@Trips defaultParquetReadOptions{rowRange = Just (0, 10)} \"trips.parquet\"+@+-} readParquetWithOpts ::     forall cols.     (KnownSchema cols) =>     ParquetReadOptions -> FilePath -> IO (TypedDataFrame cols) readParquetWithOpts opts path =-    Parquet.readParquetWithOpts opts path >>= freezeOrThrow @cols+    Parquet.readParquetWithOpts (schemaOptions @cols opts) path+        >>= freezeOrThrow @cols --- | Read a directory\/glob of Parquet files into a typed DataFrame.+{- | Read a directory\/glob of Parquet files into a typed DataFrame.++==== __Example__+@+ghci> trips <- readParquetFiles \@Trips \".\/data\/trips\/*.parquet\"+@+-} readParquetFiles ::     forall cols. (KnownSchema cols) => FilePath -> IO (TypedDataFrame cols)-readParquetFiles path = Parquet.readParquetFiles path >>= freezeOrThrow @cols+readParquetFiles path =+    Parquet.readParquetFilesWithOpts+        (schemaOptions @cols defaultParquetReadOptions)+        path+        >>= freezeOrThrow @cols