所以我试图从Riot API解析JSON，并且我在尝试获取特定的哈希表时遇到了一些麻烦。根据我的理解，api调用给了我一个哈希表，在这个表中有另一个哈希表，在该表中，是一个大的，可变数量的哈希表，每个哈希表都有另一个哈希表。我得到的表
{"summonerId":35979437,"modifyDate":1428864068000,"champions":
[{"id":40,"stats":
{"totalSessionsPlayed":2,"totalSessionsLost":1,"totalSessionsWon":1,"totalChampionKills":0,"totalDamageDealt":41909,"totalDamageTaken":27441,"mostChampionKillsPerSession":0,"totalMinionKills":22,"totalDoubleKills":0,"totalTripleKills":0,"totalQuadraKills":0,"totalPentaKills":0,"totalUnrealKills":0,"totalDeathsPerSession":4,"totalGoldEarned":15959,"mostSpellsCast":0,"totalTurretsKilled":0,"totalPhysicalDamageDealt":13865,"totalMagicDamageDealt":28042,"totalFirstBlood":0,"totalAssists":28,"maxChampionsKilled":0,"maxNumDeaths":4}},
{"id":111,"stats":
{"totalSessionsPlayed":8,"totalSessionsLost":6,"totalSessionsWon":2,"totalChampionKills":28,"totalDamageDealt":846416,"totalDamageTaken":248816,"mostChampionKillsPerSession":9,"totalMinionKills":337,"totalDoubleKills":2,"totalTripleKills":0,"totalQuadraKills":0,"totalPentaKills":0,"totalUnrealKills":0,"totalDeathsPerSession":45,"totalGoldEarned":80278,"mostSpellsCast":0,"totalTurretsKilled":4,"totalPhysicalDamageDealt":221463,"totalMagicDamageDealt":519678,"totalFirstBlood":0,"totalAssists":84,"maxChampionsKilled":9,"maxNumDeaths":10}},
这种情况一直持续下去，最多只有120个独特的＆＃34; id＆＃34;具有统计表的表。我试图访问{"id":0,"stats":表。似乎api将这个大块作为哈希表返回，所以我可以使用
(define ranked-summoner (hash-ref ranked-hash-json (string->symbol "champions")))
访问哈希表的LIST，但我不确定如何在该列表中查找"id":0哈希值。
我的相关代码如下：
(define api-id-request "https://na.api.pvp.net/api/lol/na/v1.3/stats/by-summoner/35979437/ranked?api_key=8864143b-a987-45a8-b49d-53c0a7677100")
（define（query-for-id summoner-id） （定义ranking-stats（string-＆gt; url（string-replace api-id-request＆＃34; SUMMONER_ID＆＃34; summoner-id）））
; Define request parameters for RANKED-STATS, setup for output
(define ranked (get-pure-port ranked-stats #:redirections 5))
(define ranked-hash-str (port->string ranked))
(define ranked-hash-json (string->jsexpr ranked-hash-str))
(define ranked-summoner (hash-ref ranked-hash-json (string->symbol "champions")))
;vvvv doesn't work, i need to find the hash that id=0, then grab the stats from there
(define ranked-champ-id (hash-ref (car ranked-summoner) (string->symbol "id")))
(define ranked-pentas (hash-ref ranked-champ-id (string->symbol "totalPentaKills")))
（printf＆＃34; Pentakills：~a \ n＆＃34;排名 - pentas） ）
答案 0 :(得分：0)
假设JSON字符串被解析为jsexpr，如下所示：
(define js
#hasheq((summonerId . 35979437)
(modifyDate . 1428864068000)
(champions
.
(#hasheq((id . 40)
(stats
.
#hasheq((totalSessionsPlayed . 2)
(totalSessionsLost . 1)
(totalSessionsWon . 1)
(totalChampionKills . 0)
(totalDamageDealt . 41909)
(totalDamageTaken . 27441)
(mostChampionKillsPerSession . 0)
(totalMinionKills . 22)
(totalDoubleKills . 0)
(totalTripleKills . 0)
(totalQuadraKills . 0)
(totalPentaKills . 0)
(totalUnrealKills . 0)
(totalDeathsPerSession . 4)
(totalGoldEarned . 15959)
(mostSpellsCast . 0)
(totalTurretsKilled . 0)
(totalPhysicalDamageDealt . 13865)
(totalMagicDamageDealt . 28042)
(totalFirstBlood . 0)
(totalAssists . 28)
(maxChampionsKilled . 0)
(maxNumDeaths . 4))))
#hasheq((id . 0)
(stats
.
#hasheq((totalSessionsPlayed . 8)
(totalSessionsLost . 6)
(totalSessionsWon . 2)
(totalChampionKills . 28)
(totalDamageDealt . 846416)
(totalDamageTaken . 248816)
(mostChampionKillsPerSession . 9)
(totalMinionKills . 337)
(totalDoubleKills . 2)
(totalTripleKills . 0)
(totalQuadraKills . 0)
(totalPentaKills . 0)
(totalUnrealKills . 0)
(totalDeathsPerSession . 45)
(totalGoldEarned . 80278)
(mostSpellsCast . 0)
(totalTurretsKilled . 4)
(totalPhysicalDamageDealt . 221463)
(totalMagicDamageDealt . 519678)
(totalFirstBlood . 0)
(totalAssists . 84)
(maxChampionsKilled . 9)
(maxNumDeaths . 10))))))))
然后champions是list hash个。因此，您需要像这样检查每一个：
(define champs (hash-ref js 'champions))
(for/or ([champ (in-list champs)])
(cond [(= 0 (hash-ref champ 'id)) champ]
[else #f]))
;; =>
;; '#hasheq((id . 0)
;; (stats
;; .
;; #hasheq((totalSessionsPlayed . 8)
;; (totalSessionsLost . 6)
;; (totalSessionsWon . 2)
;; (totalChampionKills . 28)
;; (totalDamageDealt . 846416)
;; (totalDamageTaken . 248816)
;; (mostChampionKillsPerSession . 9)
;; (totalMinionKills . 337)
;; (totalDoubleKills . 2)
;; (totalTripleKills . 0)
;; (totalQuadraKills . 0)
;; (totalPentaKills . 0)
;; (totalUnrealKills . 0)
;; (totalDeathsPerSession . 45)
;; (totalGoldEarned . 80278)
;; (mostSpellsCast . 0)
;; (totalTurretsKilled . 4)
;; (totalPhysicalDamageDealt . 221463)
;; (totalMagicDamageDealt . 519678)
;; (totalFirstBlood . 0)
;; (totalAssists . 84)
;; (maxChampionsKilled . 9)
;; (maxNumDeaths . 10))))
如果他们的API将champions作为哈希值id返回，那将会更方便。但是根据你所说的，他们将其作为JSON array返回 - 其中，Racket的json模块将其解析为球拍list - 所以你必须逐个检查元素。
答案 1 :(得分：0)
写下这个功能：
(define (champion-by-id id champions)
(findf (λ (champ)
(eq? (hash-ref champ 'id) id)) champions))
然后像这样使用它：
(champion-by-id 0 ranked-summoner)