JSON配列をCSVに変換
JSONをCSVに変換するソリューションを探しています。ほとんどのソリューションは、JSONがオブジェクトの配列ではなく単一のオブジェクトであることを期待しているようです。
私がここから試したすべてのソリューションは、 このサイトをカーリングする からの私の入力で壊れるようです。
入力がオブジェクトではなく配列である場合、JSONをjqまたは別のツールを使用してCSVに変換するにはどうすればよいですか。
[
{
"id": "4",
"link": "https://pressbooks.online.ucf.edu/amnatgov/",
"metadata": {
"@context": "http://schema.org",
"@type": "Book",
"name": "American Government",
"inLanguage": "en",
"copyrightYear": "2016",
"disambiguatingDescription": "The content of this textbook has been developed and arranged to provide a logical progression from the fundamental principles of institutional design at the founding, to avenues of political participation, to thorough coverage of the political structures that constitute American government. The book builds upon what students have already learned and emphasizes connections between topics as well as between theory and applications. The goal of each section is to enable students not just to recognize concepts, but to work with them in ways that will be useful in later courses, future careers, and as engaged citizens. ",
"image": "https://pressbooks.online.ucf.edu/app/uploads/sites/4/2020/01/American-Government.png",
"isBasedOn": "https://ucf-dev.pb.unizin.org/pos2041",
"author": [
{
"@type": "Person",
"name": "OpenStax"
}
],
"datePublished": "2016-01-06",
"copyrightHolder": {
"@type": "Organization",
"name": "cnxamgov"
},
"license": {
"@type": "CreativeWork",
"url": "https://creativecommons.org/licenses/by/4.0/",
"name": "CC BY (Attribution)"
}
},
"_links": {
"api": [
{
"href": "https://pressbooks.online.ucf.edu/amnatgov/wp-json/"
}
],
"metadata": [
{
"href": "https://pressbooks.online.ucf.edu/amnatgov/wp-json/pressbooks/v2/metadata"
}
],
"self": [
{
"href": "https://pressbooks.online.ucf.edu/wp-json/pressbooks/v2/books/4"
}
]
}
}
]
望ましいフォーマット：
id, link, context, type, name, inLanguage, image, author_type, author_name, license_type, license_url, license_name
問題は、表示するJSONが配列であることではなく、配列の各要素（1つしかありません）がかなり複雑な構造であることです。各配列エントリから関連するデータをより短いフラット配列に抽出し、jqの_@csv_を使用してCSVに変換するのは簡単です。
_jq -r '.[] | [
.id,
.link,
.metadata."@context",
.metadata."@type",
.metadata.name,
.metadata.inLanguage,
.metadata.image,
.metadata.author[0]."@type",
.metadata.author[0].name,
.metadata.license."@type",
.metadata.license.url,
.metadata.license.name
] | @csv' file.json
_...しかし、私たちが最初の作者だけに興味があると断定せざるを得ないことに注意してください（_.metadata.author_サブ構造は配列です）。
出力：
_"4","https://pressbooks.online.ucf.edu/amnatgov/","http://schema.org","Book","American Government","en","https://pressbooks.online.ucf.edu/app/uploads/sites/4/2020/01/American-Government.png","Person","OpenStax","CreativeWork","https://creativecommons.org/licenses/by/4.0/","CC BY (Attribution)"
__;_を区切り文字として使用して、すべての著者名を連結した著者名文字列を（および同様に著者タイプについて）作成するには、上記の_.metadata.author[0].name_の代わりに[.metadata.author[].name]|join(";")（および[.metadata.author[]."@type"]|join(";") for the type）ので、コマンドは
_jq -r '.[] | [
.id,
.link,
.metadata."@context",
.metadata."@type",
.metadata.name,
.metadata.inLanguage,
.metadata.image,
( [ .metadata.author[]."@type" ] | join(";") ),
( [ .metadata.author[].name ] | join(";") ),
.metadata.license."@type",
.metadata.license.url,
.metadata.license.name
] | @csv' file.json
_Miller（ https://github.com/johnkerl/miller ）を使用すると、JSONを「フラット」にして実行できます
mlr --j2c cat input.json >output.csv
+----+---------------------------------------------+-------------------+----------------+---------------------+---------------------+------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------+---------------------------------------+-------------------------+------------------------+------------------------+--------------------------------+-------------------------------+------------------------+----------------------------------------------+-----------------------+-----------------------------------------------------+---------------------------------------------------------------------------+-----------------------------------------------------------------+
| id | link | metadata:@context | metadata:@type | metadata:name | metadata:inLanguage | metadata:copyrightYear | metadata:disambiguatingDescription | metadata:image | metadata:isBasedOn | metadata:author:0:@type | metadata:author:0:name | metadata:datePublished | metadata:copyrightHolder:@type | metadata:copyrightHolder:name | metadata:license:@type | metadata:license:url | metadata:license:name | _links:api:0:href | _links:metadata:0:href | _links:self:0:href |
+----+---------------------------------------------+-------------------+----------------+---------------------+---------------------+------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------+---------------------------------------+-------------------------+------------------------+------------------------+--------------------------------+-------------------------------+------------------------+----------------------------------------------+-----------------------+-----------------------------------------------------+---------------------------------------------------------------------------+-----------------------------------------------------------------+
| 4 | https://pressbooks.online.ucf.edu/amnatgov/ | http://schema.org | Book | American Government | en | 2016 | The content of this textbook has been developed and arranged to provide a logical progression from the fundamental principles of institutional design at the founding, to avenues of political participation, to thorough coverage of the political structures that constitute American government. The book builds upon what students have already learned and emphasizes connections between topics as well as between theory and applications. The goal of each section is to enable students not just to recognize concepts, but to work with them in ways that will be useful in later courses, future careers, and as engaged citizens. | https://pressbooks.online.ucf.edu/app/uploads/sites/4/2020/01/American-Government.png | https://ucf-dev.pb.unizin.org/pos2041 | Person | OpenStax | 2016-01-06 | Organization | cnxamgov | CreativeWork | https://creativecommons.org/licenses/by/4.0/ | CC BY (Attribution) | https://pressbooks.online.ucf.edu/amnatgov/wp-json/ | https://pressbooks.online.ucf.edu/amnatgov/wp-json/pressbooks/v2/metadata | https://pressbooks.online.ucf.edu/wp-json/pressbooks/v2/books/4 |
+----+---------------------------------------------+-------------------+----------------+---------------------+---------------------+------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------+---------------------------------------+-------------------------+------------------------+------------------------+--------------------------------+-------------------------------+------------------------+----------------------------------------------+-----------------------+-----------------------------------------------------+---------------------------------------------------------------------------+-----------------------------------------------------------------+
次に、必要なフィールドを抽出し、それらを使用して名前を変更します
mlr -I --csv cut -f "id","link","metadata:@context","metadata:@type","metadata:name","metadata:inLanguage","metadata:image","metadata:author:0:@type","metadata:author:0:name","metadata:license:@type","metadata:license:url","metadata:license:name" \
then label id,link,context,type,name,inLanguage,image,author_type,author_name,license_type,license_url,license_name output.csv
出力は
+----+---------------------------------------------+-------------------+------+---------------------+------------+---------------------------------------------------------------------------------------+-------------+-------------+--------------+----------------------------------------------+---------------------+
| id | link | context | type | name | inLanguage | image | author_type | author_name | license_type | license_url | license_name |
+----+---------------------------------------------+-------------------+------+---------------------+------------+---------------------------------------------------------------------------------------+-------------+-------------+--------------+----------------------------------------------+---------------------+
| 4 | https://pressbooks.online.ucf.edu/amnatgov/ | http://schema.org | Book | American Government | en | https://pressbooks.online.ucf.edu/app/uploads/sites/4/2020/01/American-Government.png | Person | OpenStax | CreativeWork | https://creativecommons.org/licenses/by/4.0/ | CC BY (Attribution) |
+----+---------------------------------------------+-------------------+------+---------------------+------------+---------------------------------------------------------------------------------------+-------------+-------------+--------------+----------------------------------------------+---------------------+