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[英]How to query/extract array elements from within a pyspark dataframe
[英]Firebase Database - How to extract elements from a documents query?
我有一個 python 腳本,它通過下面的代碼從數據庫請求數據:
from datetime import datetime
import re
global dateTimeObj
dateTimeObj = datetime.now()
path = db.collection(u'users').document(u'a@a.com')
doc_ref = path.collection(u'feedback').order_by(u'time_stamp').stream()
for doc in doc_ref:
a = u'{} => {}'.format(doc.id, doc.to_dict())
print(a)
輸出:
feedback_1 => {'feedback_sub_item': 'feedback sub item', 'feedback': 'feedback message', 'record_id': '111', 'cycle_id': 'normal', 'rating': 3.5, 'time_stamp': '02/28/2020 16:15:58'}
feedback_2 => {'feedback_sub_item': 'feedback sub item', 'feedback': 'feedback message', 'record_id': '112', 'cycle_id': 'normal', 'rating': 4, 'time_stamp': '02/28/2020 16:16:52'}
我的問題是,如何轉換此消息以根據 time_stamp 字段從上次反饋中提取參數?
我想要的輸出是:
Feedback_number = feedback_2
feedback_sub_item = feedback sub item
feedback = feedback message
record_id = 112
cycle_id = normal
rating = 4
time_stamp = 02/28/2020 16:16:52
謝謝
要提取字典,您可以使用 split 函數。 然后你可以用它的鍵遍歷這個字典。
為此,您可以使用“for”循環來顯示字典中包含的值。
# a is your last feedback
new_list = a.split("=>")
new_dict = eval(new_list[1])
print("feedback_number = ", new_list[0])
for key in new_dict:
print(key," = ",new_dict[key])
通過此示例,您將獲得:
feedback_number = feedback_2
feedback_sub_item = feedback sub item
feedback = feedback message
record_id = 112
cycle_id = normal
rating = 4
time_stamp = 02/28/2020 16:16:52
我希望能回答你的問題
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