# FlatMap クラス
コレクションの各 `DynamicFrame` に変換が適用されます。結果が単一の `DynamicFrame` にフラット化されるのではなく、コレクションとして保存されます。
## FlatMap の例
次のスニペットの例は、`FlatMap` に適用したときに、`ResolveChoice` 変換を動的フレームのコレクションで使用する方法を示しています。入力に使用されるデータは、プレースホルダ Amazon S3 アドレス `s3://bucket/path-for-data/sample.json` にある JSON の中にあって、次のデータが含まれています。
### JSON データの例
```
[{
"firstname": "Arnav",
"lastname": "Desai",
"address": {
"street": "6 Anyroad Avenue",
"city": "London",
"state": "England",
"country": "UK"
},
"phone": 17235550101,
"affiliations": [
"General Anonymous Example Products",
"Example Independent Research",
"Government Department of Examples"
]
},
{
"firstname": "Mary",
"lastname": "Major",
"address": {
"street": "7821 Spot Place",
"city": "Centerville",
"state": "OK",
"country": "US"
},
"phone": 19185550023,
"affiliations": [
"Example Dot Com",
"Example Independent Research",
"Example.io"
]
},
{
"firstname": "Paulo",
"lastname": "Santos",
"address": {
"street": "123 Maple Street",
"city": "London",
"state": "Ontario",
"country": "CA"
},
"phone": 12175550181,
"affiliations": [
"General Anonymous Example Products",
"Example Dot Com"
]
}]
```
**Example ResolveChoice を DynamicFrameCollection に適用し、出力を表示します。**
```
#Read DynamicFrame
datasource = glueContext.create_dynamic_frame_from_options("s3", connection_options = {"paths":["s3://bucket/path/to/file/mysamplejson.json"]}, format="json")
datasource.printSchema()
datasource.show()
## Split to create a DynamicFrameCollection
split_frame=datasource.split_fields(["firstname","lastname","address"],"personal_info","business_info")
split_frame.keys()
print("---")
## Use FlatMap to run ResolveChoice
kwargs = {"choice": "cast:string"}
flat = FlatMap.apply(split_frame, ResolveChoice, frame_name="frame", transformation_ctx='tcx', **kwargs)
flat.keys()
##Select one of the DynamicFrames
personal_info = flat.select("personal_info")
personal_info.printSchema()
personal_info.show()
print("---")
business_info = flat.select("business_info")
business_info.printSchema()
business_info.show()
```
`FlatMap.apply` を呼び出すとき、`frame_name` パラメータは `"frame"` である**必要があります**。現在、他の値は受け付けられません。
### 出力例
```
root
|-- firstname: string
|-- lastname: string
|-- address: struct
| |-- street: string
| |-- city: string
| |-- state: string
| |-- country: string
|-- phone: long
|-- affiliations: array
| |-- element: string
---
{
"firstname": "Mary",
"lastname": "Major",
"address": {
"street": "7821 Spot Place",
"city": "Centerville",
"state": "OK",
"country": "US"
},
"phone": 19185550023,
"affiliations": [
"Example Dot Com",
"Example Independent Research",
"Example.io"
]
}
{
"firstname": "Paulo",
"lastname": "Santos",
"address": {
"street": "123 Maple Street",
"city": "London",
"state": "Ontario",
"country": "CA"
},
"phone": 12175550181,
"affiliations": [
"General Anonymous Example Products",
"Example Dot Com"
]
}
---
root
|-- firstname: string
|-- lastname: string
|-- address: struct
| |-- street: string
| |-- city: string
| |-- state: string
| |-- country: string
{
"firstname": "Mary",
"lastname": "Major",
"address": {
"street": "7821 Spot Place",
"city": "Centerville",
"state": "OK",
"country": "US"
}
}
{
"firstname": "Paulo",
"lastname": "Santos",
"address": {
"street": "123 Maple Street",
"city": "London",
"state": "Ontario",
"country": "CA"
}
}
---
root
|-- phone: long
|-- affiliations: array
| |-- element: string
{
"phone": 19185550023,
"affiliations": [
"Example Dot Com",
"Example Independent Research",
"Example.io"
]
}
{
"phone": 12175550181,
"affiliations": [
"General Anonymous Example Products",
"Example Dot Com"
]
}
```
## 方法
+ [\_\_call\_\_](#aws-glue-api-crawler-pyspark-transforms-flat-map-__call__)
+ [適用](#aws-glue-api-crawler-pyspark-transforms-flat-map-apply)
+ [名前](#aws-glue-api-crawler-pyspark-transforms-flat-map-name)
+ [describeArgs](#aws-glue-api-crawler-pyspark-transforms-flat-map-describeArgs)
+ [describeReturn](#aws-glue-api-crawler-pyspark-transforms-flat-map-describeReturn)
+ [describeTransform](#aws-glue-api-crawler-pyspark-transforms-flat-map-describeTransform)
+ [describeErrors](#aws-glue-api-crawler-pyspark-transforms-flat-map-describeErrors)
+ [説明](#aws-glue-api-crawler-pyspark-transforms-flat-map-describe)
## \_\_call\_\_(dfc, BaseTransform, frame\_name, transformation\_ctx = "", \*\*base\_kwargs)
変換をコレクション内の各 `DynamicFrame` に適用し、結果をフラット化します。
+ `dfc` – フラットマップする `DynamicFrameCollection` (必須)。
+ `BaseTransform` – コレクションの各メンバーに適用する `GlueTransform` から派生した変換 (必須)。
+ `frame_name` – コレクションの要素を渡す引数名 (必須)。
+ `transformation_ctx` - 状態情報を識別するために使用される一意の文字列 (オプション)。
+ `base_kwargs` – ベース変換に渡す引数 (必須)。
ソース `DynamicFrameCollection` の各 `DynamicFrame` に変換を適用して作成された新しい `DynamicFrameCollection` を返します。
## apply(cls, \*args, \*\*kwargs)
継承元は `GlueTransform` [適用](aws-glue-api-crawler-pyspark-transforms-GlueTransform.md#aws-glue-api-crawler-pyspark-transforms-GlueTransform-apply)。
## name(cls)
継承元は `GlueTransform` [名前](aws-glue-api-crawler-pyspark-transforms-GlueTransform.md#aws-glue-api-crawler-pyspark-transforms-GlueTransform-name)。
## describeArgs(cls)
継承元は `GlueTransform` [describeArgs](aws-glue-api-crawler-pyspark-transforms-GlueTransform.md#aws-glue-api-crawler-pyspark-transforms-GlueTransform-describeArgs)。
## describeReturn(cls)
継承元は `GlueTransform` [describeReturn](aws-glue-api-crawler-pyspark-transforms-GlueTransform.md#aws-glue-api-crawler-pyspark-transforms-GlueTransform-describeReturn)。
## describeTransform(cls)
継承元は `GlueTransform` [describeTransform](aws-glue-api-crawler-pyspark-transforms-GlueTransform.md#aws-glue-api-crawler-pyspark-transforms-GlueTransform-describeTransform)。
## describeErrors(cls)
継承元は `GlueTransform` [describeErrors](aws-glue-api-crawler-pyspark-transforms-GlueTransform.md#aws-glue-api-crawler-pyspark-transforms-GlueTransform-describeErrors)。
## describe(cls)
継承元は `GlueTransform` [説明](aws-glue-api-crawler-pyspark-transforms-GlueTransform.md#aws-glue-api-crawler-pyspark-transforms-GlueTransform-describe)。