如何在python中从JSON列表导出嵌套对象_Python_Json_Mongodb

如何在python中从JSON列表导出嵌套对象

python json mongodb

如何在python中从JSON列表导出嵌套对象,python,json,mongodb,Python,Json,Mongodb,我不熟悉MongoDB和JSON格式。我在MongoDB集合中使用了以下JSON格式。我想从每个内部对象中获取值2、值4和值time，并将它们导出到CSV。此外，每个文档的内部对象数量可以从1到4个不等。在python中如何实现这一点 [{"object":[ {"value1":number, "value2"":number, "value3"":number, "value4"":"code", "value5"":number,

我不熟悉MongoDB和JSON格式。我在MongoDB集合中使用了以下JSON格式。我想从每个内部对象中获取值2、值4和值time，并将它们导出到CSV。此外，每个文档的内部对象数量可以从1到4个不等。在python中如何实现这一点

[{"object":[
    {"value1":number,
     "value2"":number,
     "value3"":number,
     "value4"":"code",
     "value5"":number,
     "value6"":"name"}
     ,
     {"value1":number,
      "value2":number,
      "value3":number,
      "value4":"code",
      "value5":number,
      "value6":"name"}]
     ,
 "time":1550666169274}]"""

欢迎来到堆栈溢出

您的格式在语法上不正确。你还应该（根据规则）提供一个你迄今为止尝试过的例子。你是新来的，所以你得到了通行证，但请记住这一点，以备将来使用=）

不太清楚你在问什么。这似乎是两个问题——1。如何访问和捕获数据结构中的数据，2。如何将捕获的数据写入csv

回答第一部分（访问和捕获数据）：你有清单和字典。要访问列表中的值，请使用后面的值的索引号（从0开始作为第一个索引号）

例如，如果我有列表

l=['zero'、'one'、'two']

我可以通过

l[1]

访问字符串“one”，其中1是列表

中“one”的索引号

要访问字典中的内容，可以使用它的键。例如，

d={'key'：'value'}

使用

d['key']

获取其对应的值-

值'

因此，假设您的数据实际上如下所示：

my_json = [
  {
    "object":[
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      },
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      }
    ],
    "time":1550666169274
  }
]

my_json[0]
>>> {'object': [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}], 'time': 1550666169274}

my_json[0]['object']
>>> [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}]

my_json[0]['time']
>>> 1550666169274

all_docs = [] # create an empty list to hold further captured data

for obj in range(len(my_json)): # for each 'thing' in this list
  obj_time = my_json[obj]['time'] # grab the time
  values_sought = [] # create an empty list to hold further captured data

  for dictionary in my_json[obj]['object']: # for each 'thing' in the 'object''s list
    val_2 = dictionary['value2'] # grab the necessary values
    val_4 = dictionary['value4']
    values_sought.append((val_2, val_4)) # append them to the empty list above

  print(obj_time, values_sought)
  >>> 1550666169274 [(1, 'code'), (1, 'code')]

  all_docs.append((obj_time, values_sought)) # append each document's data to the all_docs list

print(all_docs)
>>> [(1550666169274, [(1, 'code'), (1, 'code')])]

[(1550666169274, [(1, 'code'), (1, 'code')])
 (1550666169275, [(1, 'code'), (1, 'code')]),]

document_1 = all_docs[0]
document_1_data_all = all_docs[1]
document_1_data_1 = all_docs[1][0] # (or iterate)

document_2 = all_docs[1]

你所拥有的是一份包含字典的清单；“object”键的值是列表，包含字典，“time”键的值是字符串

因此，您可以通过以下方式访问数据：

my_json = [
  {
    "object":[
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      },
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      }
    ],
    "time":1550666169274
  }
]

my_json[0]
>>> {'object': [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}], 'time': 1550666169274}

my_json[0]['object']
>>> [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}]

my_json[0]['time']
>>> 1550666169274

all_docs = [] # create an empty list to hold further captured data

for obj in range(len(my_json)): # for each 'thing' in this list
  obj_time = my_json[obj]['time'] # grab the time
  values_sought = [] # create an empty list to hold further captured data

  for dictionary in my_json[obj]['object']: # for each 'thing' in the 'object''s list
    val_2 = dictionary['value2'] # grab the necessary values
    val_4 = dictionary['value4']
    values_sought.append((val_2, val_4)) # append them to the empty list above

  print(obj_time, values_sought)
  >>> 1550666169274 [(1, 'code'), (1, 'code')]

  all_docs.append((obj_time, values_sought)) # append each document's data to the all_docs list

print(all_docs)
>>> [(1550666169274, [(1, 'code'), (1, 'code')])]

[(1550666169274, [(1, 'code'), (1, 'code')])
 (1550666169275, [(1, 'code'), (1, 'code')]),]

document_1 = all_docs[0]
document_1_data_all = all_docs[1]
document_1_data_1 = all_docs[1][0] # (or iterate)

document_2 = all_docs[1]

或者，您可以像这样迭代对象列表（如果列表中有多个对象，则很有用）：

my_json[0]

是一个字典-因此您可以访问它的值（字典列表），如下所示：

my_json = [
  {
    "object":[
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      },
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      }
    ],
    "time":1550666169274
  }
]

my_json[0]
>>> {'object': [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}], 'time': 1550666169274}

my_json[0]['object']
>>> [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}]

my_json[0]['time']
>>> 1550666169274

all_docs = [] # create an empty list to hold further captured data

for obj in range(len(my_json)): # for each 'thing' in this list
  obj_time = my_json[obj]['time'] # grab the time
  values_sought = [] # create an empty list to hold further captured data

  for dictionary in my_json[obj]['object']: # for each 'thing' in the 'object''s list
    val_2 = dictionary['value2'] # grab the necessary values
    val_4 = dictionary['value4']
    values_sought.append((val_2, val_4)) # append them to the empty list above

  print(obj_time, values_sought)
  >>> 1550666169274 [(1, 'code'), (1, 'code')]

  all_docs.append((obj_time, values_sought)) # append each document's data to the all_docs list

print(all_docs)
>>> [(1550666169274, [(1, 'code'), (1, 'code')])]

[(1550666169274, [(1, 'code'), (1, 'code')])
 (1550666169275, [(1, 'code'), (1, 'code')]),]

document_1 = all_docs[0]
document_1_data_all = all_docs[1]
document_1_data_1 = all_docs[1][0] # (or iterate)

document_2 = all_docs[1]

这是一个列表，所以再次使用索引：

my_json[0]['object'][0] # or iterate through the list of objects as above
>>> {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}

给你一本字典，所以使用它的关键：

my_json[0]['object'][0]['value2']
>>> 1

等等

由于“每个文档的内部对象数量可以从1到4个不等”，因此您确实希望遍历“对象”包含的字典列表。您可以这样做：

my_json = [
  {
    "object":[
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      },
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      }
    ],
    "time":1550666169274
  }
]

my_json[0]
>>> {'object': [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}], 'time': 1550666169274}

my_json[0]['object']
>>> [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}]

my_json[0]['time']
>>> 1550666169274

all_docs = [] # create an empty list to hold further captured data

for obj in range(len(my_json)): # for each 'thing' in this list
  obj_time = my_json[obj]['time'] # grab the time
  values_sought = [] # create an empty list to hold further captured data

  for dictionary in my_json[obj]['object']: # for each 'thing' in the 'object''s list
    val_2 = dictionary['value2'] # grab the necessary values
    val_4 = dictionary['value4']
    values_sought.append((val_2, val_4)) # append them to the empty list above

  print(obj_time, values_sought)
  >>> 1550666169274 [(1, 'code'), (1, 'code')]

  all_docs.append((obj_time, values_sought)) # append each document's data to the all_docs list

print(all_docs)
>>> [(1550666169274, [(1, 'code'), (1, 'code')])]

[(1550666169274, [(1, 'code'), (1, 'code')])
 (1550666169275, [(1, 'code'), (1, 'code')]),]

document_1 = all_docs[0]
document_1_data_all = all_docs[1]
document_1_data_1 = all_docs[1][0] # (or iterate)

document_2 = all_docs[1]

假设您有两个文档（在顶层），所有的文档都是这样的：

my_json = [
  {
    "object":[
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      },
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      }
    ],
    "time":1550666169274
  }
]

my_json[0]
>>> {'object': [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}], 'time': 1550666169274}

my_json[0]['object']
>>> [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}]

my_json[0]['time']
>>> 1550666169274

all_docs = [] # create an empty list to hold further captured data

for obj in range(len(my_json)): # for each 'thing' in this list
  obj_time = my_json[obj]['time'] # grab the time
  values_sought = [] # create an empty list to hold further captured data

  for dictionary in my_json[obj]['object']: # for each 'thing' in the 'object''s list
    val_2 = dictionary['value2'] # grab the necessary values
    val_4 = dictionary['value4']
    values_sought.append((val_2, val_4)) # append them to the empty list above

  print(obj_time, values_sought)
  >>> 1550666169274 [(1, 'code'), (1, 'code')]

  all_docs.append((obj_time, values_sought)) # append each document's data to the all_docs list

print(all_docs)
>>> [(1550666169274, [(1, 'code'), (1, 'code')])]

[(1550666169274, [(1, 'code'), (1, 'code')])
 (1550666169275, [(1, 'code'), (1, 'code')]),]

document_1 = all_docs[0]
document_1_data_all = all_docs[1]
document_1_data_1 = all_docs[1][0] # (or iterate)

document_2 = all_docs[1]

现在，您可以像这样迭代此列表和元组：

my_json = [
  {
    "object":[
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      },
      {
        "value1":1,
        "value2":1,
        "value3":1,
        "value4":"code",
        "value5":1,
        "value6":"name"
      }
    ],
    "time":1550666169274
  }
]

my_json[0]
>>> {'object': [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}], 'time': 1550666169274}

my_json[0]['object']
>>> [{'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}, {'value1': 1, 'value2': 1, 'value3': 1, 'value4': 'code', 'value5': 1, 'value6': 'name'}]

my_json[0]['time']
>>> 1550666169274

all_docs = [] # create an empty list to hold further captured data

for obj in range(len(my_json)): # for each 'thing' in this list
  obj_time = my_json[obj]['time'] # grab the time
  values_sought = [] # create an empty list to hold further captured data

  for dictionary in my_json[obj]['object']: # for each 'thing' in the 'object''s list
    val_2 = dictionary['value2'] # grab the necessary values
    val_4 = dictionary['value4']
    values_sought.append((val_2, val_4)) # append them to the empty list above

  print(obj_time, values_sought)
  >>> 1550666169274 [(1, 'code'), (1, 'code')]

  all_docs.append((obj_time, values_sought)) # append each document's data to the all_docs list

print(all_docs)
>>> [(1550666169274, [(1, 'code'), (1, 'code')])]

[(1550666169274, [(1, 'code'), (1, 'code')])
 (1550666169275, [(1, 'code'), (1, 'code')]),]

document_1 = all_docs[0]
document_1_data_all = all_docs[1]
document_1_data_1 = all_docs[1][0] # (or iterate)

document_2 = all_docs[1]

…等等

对于第二部分，写入csv，这取决于您希望如何格式化它。我建议您看看python的内置语言

希望对您有所帮助

欢迎来到Stack Overflow