Extraire des données spécifiques d'un JSON complexe

introduction

À l'origine, il s'agit d'un JSON pour simplement exprimer une structure de données compliquée, mais cela peut devenir compliqué en raison d'une conception incorrecte ou de spécifications indécises. La complexité ici est que vous ne savez pas quel niveau de données vous souhaitez obtenir de JSON et combien.

Le but de cette fois est d'acquérir des données spécifiques à partir d'un JSON aussi compliqué.

Ce but

input

test.json

{"a": [{
  "b": 1, 
  "c": [{
    "star": [{"Deneb": "Deneb", "Altair": "Altair", "Vega": "Vega"}], 
    "d": [2,3]
    }], 
  "e": {"g": "x"}
  }],
 "f": "y",
}

output

[{"Deneb": "Deneb", "Altair": "Altair", "Vega": "Vega"}]

Les données que vous souhaitez obtenir sont

• Je ne sais pas de quel niveau il s'agit
• Je ne sais pas combien

→ Rechercher JSON de manière récursive

la mise en oeuvre

python

import json

def search(arg, cond):
    res =[]
    if cond(arg):
        res.append(arg)
    if isinstance(arg, list):
        for item in arg:
            res += search(item, cond)
    elif isinstance(arg, dict):
        for value in arg.values():
            res += search(value, cond)
    return res

def has_star_key(arg):
    if isinstance(arg, dict):
        return arg.keys() == {"Deneb", "Altair", "Vega"}
            
def get_star(arg):
    return search(arg, has_star_key)


if __name__ == "__main__":
    with open('test.json', encoding='utf-8') as f:
        data = json.load(f)
        print(get_star(data)) # [{"Deneb": "Deneb", "Altair": "Altair", "Vega": "Vega"}]

J'ai pu obtenir les données souhaitées!

Commentaire

① ** Fonction de recherche JSON **

python

def search(arg, cond):
    res =[]
    if cond(arg):
        res.append(arg)
    if isinstance(arg, list):
        for item in arg:
            res += search(item, cond)
    elif isinstance(arg, dict):
        for value in arg.values():
            res += search(value, cond)
    return res

Premier argument: type Str ou type Int ou type List ou type Dict Deuxième argument: fonction pour déterminer si les données que vous souhaitez acquérir (fonction (2)) Valeur de retour: type de liste

② ** Fonction pour juger des données ** S'il y a des données que vous souhaitez récupérer, il renvoie True, sinon il retourne False.

python

def has_star_key(arg):
    if isinstance(arg, dict):
        return arg.keys() == {"Deneb", "Altair", "Vega"}

Premier argument: type Str ou type Int ou type List ou type Dict Valeur de retour: type booléen

③ ** Fonction pour obtenir des données **

python

def get_star(arg):
    return search(arg, has_star_key)

Premier argument: type de dictée Valeur de retour: type de liste

tester

Vérifions si les conditions sont modifiées ou si d'autres données JSON peuvent être acquises. Il peut être exécuté simplement en modifiant les conditions de jugement des données que vous souhaitez acquérir. (Changement de fonction de ② et changement de fonction d'accompagnement de ③)

** Cas 1. Obtenir toutes les données de type Str ** input

python

{"a": [{
  "b": 1, 
  "c": [{
    "star": [{"Deneb": "Deneb", "Altair": "Altair", "Vega": "Vega"}], 
    "d": [2,3]
    }], 
  "e": {"g": "x"}
  }],
 "f": "y",
}

condition

python

def has_str(s):
    return isinstance(s, str)

output

python

["Deneb", "Vega", "Altair", "x", "y"]

Peu importe le nombre de données que je souhaitais obtenir, ils l'ont bien compris.

** Cas 2. Obtenez des données spécifiques de JSON avec des données volumineuses ** input

python

{"DBEngineVersions":[{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.1.73a","DBParameterGroupFamily":"mysql5.1","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.1.73a"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.1.73b","DBParameterGroupFamily":"mysql5.1","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.1.73b"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.5.40","DBParameterGroupFamily":"mysql5.5","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.5.40"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.5.40a","DBParameterGroupFamily":"mysql5.5","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.5.40a"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.5.40b","DBParameterGroupFamily":"mysql5.5","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.5.40b"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.5.41","DBParameterGroupFamily":"mysql5.5","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.5.41"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.6.19a","DBParameterGroupFamily":"mysql5.6","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.6.19a"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.6.19b","DBParameterGroupFamily":"mysql5.6","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.6.19b"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.6.21","DBParameterGroupFamily":"mysql5.6","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.6.21"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.6.21b","DBParameterGroupFamily":"mysql5.6","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.6.21b"},{"Engine":"mysql","DBEngineVersionDescription":"MySQL 5.6.22","DBParameterGroupFamily":"mysql5.6","DBEngineDescription":"MySQL Community Edition","EngineVersion":"5.6.22"},
{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"11.2.0.2.v3","DBEngineVersionDescription":"Oracle 11.2.0.2.v3"},{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"11.2.0.2.v4","DBEngineVersionDescription":"Oracle 11.2.0.2.v4"},{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"11.2.0.2.v5","DBEngineVersionDescription":"Oracle 11.2.0.2.v5"},{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"11.2.0.2.v6","DBEngineVersionDescription":"Oracle 11.2.0.2.v6"},{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"11.2.0.2.v7","DBEngineVersionDescription":"Oracle 11.2.0.2.v7"},
{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"11.2.0.3.v1","DBEngineVersionDescription":"Oracle 11.2.0.3.v1"},{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"11.2.0.3.v2","DBEngineVersionDescription":"Oracle 11.2.0.3.v2"},{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"11.2.0.4.v1","DBEngineVersionDescription":"Oracle 11.2.0.4.v1"},{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"11.2.0.4.v3","DBEngineVersionDescription":"Oracle 11.2.0.4.v3"},{"Engine":"oracle-ee","DBParameterGroupFamily":"oracle-ee-12.1","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Enterprise Edition","EngineVersion":"12.1.0.1.v1","DBEngineVersionDescription":"Oracle 12.1.0.1.v1"},{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"11.2.0.2.v3","DBEngineVersionDescription":"Oracle 11.2.0.2.v3"},
{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"11.2.0.2.v4","DBEngineVersionDescription":"Oracle 11.2.0.2.v4"},{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"11.2.0.2.v5","DBEngineVersionDescription":"Oracle 11.2.0.2.v5"},{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"11.2.0.2.v6","DBEngineVersionDescription":"Oracle 11.2.0.2.v6"},{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"11.2.0.2.v7","DBEngineVersionDescription":"Oracle 11.2.0.2.v7"},{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"11.2.0.3.v1","DBEngineVersionDescription":"Oracle 11.2.0.3.v1"},{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"11.2.0.3.v2","DBEngineVersionDescription":"Oracle 11.2.0.3.v2"},
{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"11.2.0.4.v1","DBEngineVersionDescription":"Oracle 11.2.0.4.v1"},{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"11.2.0.4.v3","DBEngineVersionDescription":"Oracle 11.2.0.4.v3"},{"Engine":"oracle-se","DBParameterGroupFamily":"oracle-se-12.1","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition","EngineVersion":"12.1.0.1.v1","DBEngineVersionDescription":"Oracle 12.1.0.1.v1"},{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"11.2.0.2.v3","DBEngineVersionDescription":"Oracle 11.2.0.2.v3"},{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"11.2.0.2.v4","DBEngineVersionDescription":"Oracle 11.2.0.2.v4"},{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"11.2.0.2.v5","DBEngineVersionDescription":"Oracle 11.2.0.2.v5"},
{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"11.2.0.2.v6","DBEngineVersionDescription":"Oracle 11.2.0.2.v6"},{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"11.2.0.2.v7","DBEngineVersionDescription":"Oracle 11.2.0.2.v7"},{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"11.2.0.3.v1","DBEngineVersionDescription":"Oracle 11.2.0.3.v1"},{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"11.2.0.3.v2","DBEngineVersionDescription":"Oracle 11.2.0.3.v2"},{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"11.2.0.4.v1","DBEngineVersionDescription":"Oracle 11.2.0.4.v1"},{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-11.2","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"11.2.0.4.v3","DBEngineVersionDescription":"Oracle 11.2.0.4.v3"},
{"Engine":"oracle-se1","DBParameterGroupFamily":"oracle-se1-12.1","DefaultCharacterSet":{"CharacterSetName":"AL32UTF8","CharacterSetDescription":"Unicode 5.0 UTF-8 Universal character set"},"DBEngineDescription":"Oracle Database Standard Edition One","EngineVersion":"12.1.0.1.v1","DBEngineVersionDescription":"Oracle 12.1.0.1.v1"},{"Engine":"postgres","DBEngineVersionDescription":"PostgreSQL 9.3.1-R1","DBParameterGroupFamily":"postgres9.3","DBEngineDescription":"PostgreSQL","EngineVersion":"9.3.1"},{"Engine":"postgres","DBEngineVersionDescription":"PostgreSQL 9.3.2-R1","DBParameterGroupFamily":"postgres9.3","DBEngineDescription":"PostgreSQL","EngineVersion":"9.3.2"},{"Engine":"postgres","DBEngineVersionDescription":"PostgreSQL 9.3.3-R1","DBParameterGroupFamily":"postgres9.3","DBEngineDescription":"PostgreSQL","EngineVersion":"9.3.3"},{"Engine":"postgres","DBEngineVersionDescription":"PostgreSQL 9.3.5-R1","DBParameterGroupFamily":"postgres9.3","DBEngineDescription":"PostgreSQL","EngineVersion":"9.3.5"},{"Engine":"postgres","DBEngineVersionDescription":"PostgreSQL 9.3.6-R1","DBParameterGroupFamily":"postgres9.3","DBEngineDescription":"PostgreSQL","EngineVersion":"9.3.6"},{"Engine":"postgres","DBEngineVersionDescription":"PostgreSQL 9.4.1-R1","DBParameterGroupFamily":"postgres9.4","DBEngineDescription":"PostgreSQL","EngineVersion":"9.4.1"},{"Engine":"sqlserver-ee","DBEngineVersionDescription":"SQL Server 2008 R2 10.50.2789.0.v1","DBParameterGroupFamily":"sqlserver-ee-10.5","DBEngineDescription":"Microsoft SQL Server Enterprise Edition","EngineVersion":"10.50.2789.0.v1"},{"Engine":"sqlserver-ee","DBEngineVersionDescription":"SQL Server 2012 11.00.2100.60.v1","DBParameterGroupFamily":"sqlserver-ee-11.0","DBEngineDescription":"Microsoft SQL Server Enterprise Edition","EngineVersion":"11.00.2100.60.v1"},
{"Engine":"sqlserver-ex","DBEngineVersionDescription":"SQL Server 2008 R2 10.50.2789.0.v1","DBParameterGroupFamily":"sqlserver-ex-10.5","DBEngineDescription":"Microsoft SQL Server Express Edition","EngineVersion":"10.50.2789.0.v1"},{"Engine":"sqlserver-ex","DBEngineVersionDescription":"SQL Server 2012 11.00.2100.60.v1","DBParameterGroupFamily":"sqlserver-ex-11.0","DBEngineDescription":"Microsoft SQL Server Express Edition","EngineVersion":"11.00.2100.60.v1"},{"Engine":"sqlserver-se","DBEngineVersionDescription":"SQL Server 2008 R2 10.50.2789.0.v1","DBParameterGroupFamily":"sqlserver-se-10.5","DBEngineDescription":"Microsoft SQL Server Standard Edition","EngineVersion":"10.50.2789.0.v1"},{"Engine":"sqlserver-se","DBEngineVersionDescription":"SQL Server 2012 11.00.2100.60.v1","DBParameterGroupFamily":"sqlserver-se-11.0","DBEngineDescription":"Microsoft SQL Server Standard Edition","EngineVersion":"11.00.2100.60.v1"},{"Engine":"sqlserver-web","DBEngineVersionDescription":"SQL Server 2008 R2 10.50.2789.0.v1","DBParameterGroupFamily":"sqlserver-web-10.5","DBEngineDescription":"Microsoft SQL Server Web Edition","EngineVersion":"10.50.2789.0.v1"},{"Engine":"sqlserver-web","DBEngineVersionDescription":"SQL Server 2012 11.00.2100.60.v1","DBParameterGroupFamily":"sqlserver-web-11.0","DBEngineDescription":"Microsoft SQL Server Web Edition","EngineVersion":"11.00.2100.60.v1"}]}

condition

python

def judge_mysql51(d):
    if isinstance(d, dict):
        return "mysql5.1" in d.values()

output

python

[{"DBEngineVersionDescription": "MySQL 5.1.73a", "DBEngineDescription": "MySQL Community Edition", "Engine": "mysql", "EngineVersion": "5.1.73a",
 "DBParameterGroupFamily": "mysql5.1"}, 
{"DBEngineVersionDescription": "MySQL 5.1.73b", "DBEngineDescription": "MySQL Community Edition", "Engine": "mysql", "EngineVersion": "5.1.73b",
 "DBParameterGroupFamily": "mysql5.1"}]

J'ai pu obtenir des données spécifiques même si les données JSON étaient volumineuses.

à la fin

J'ai écrit un article plus détaillé, alors veuillez vous y référer.

• [4 étapes pour pouvoir récupérer récursivement des données spécifiques à partir de JSON complexe](https://jumpyoshim.hatenablog.com/entry/four-steps-to-get-specific-data-from-complex- json)
• L'exemple le plus simple de compréhension des fonctions récursives en Python