How to parse and remove fields from dictionary

Source Data::

ads_data = [{
    "account_id": "12345",
    "display": [
        {
            "action_type": "video_view",
            "value": "123",
            "content": [{"type" : "Adult", "subject" : " Geography "}]
        }
        ],
    "display 1": [
        {
            "action_type": "video_view",
            "value": "321"
        }
    ]
}]

I want the data like,

account_id|display|display_content_type|display_content_subject|display1
12345|123|Adult|Geography|321

As a novice I have tried various way playing on internet, but I could not. I am expecting you help in this and your help will be much appreciated.

df = []
for data in ads_data:
    keys = "|".join(data.keys())
print(keys)
for row in ads_data:
    for value in row.values():
        if isinstance(value, list):
            for i in value:
                if isinstance(i, dict):
                    df.append(",".join(i.values()))
        else:
            df.append("|".join([str(value)]))
print(df)

Your header is a subset of the keys in the nested dictionary so you'll need to define what that subset of keys is. You can use that definition to associate header labels to each key path:

Assuming the lists inside your structure only ever have one item, you could approach it like this:

keyheaders = {("account_id",)                     : "account_id",
              ("display",0,"value")               : "display",
              ("display",0,"content",0,"type")    : "display_content_type",
              ("display",0,"content",0,"subject") : "display_content_subject",
              ("display 1",0,"value")             : "display1" }

data = ["|".join(keyheaders.values())]
for row in ads_data:
    values = []                   # list of values for row
    for keyPath in keyheaders:
        value = row
        for key in keyPath:       # drill down keys and indexes
            try:    value = value[key]
            except: value = ""
        values.append(value.strip())
    data.append("|".join(values)) # assemble values into data line

print(*data,sep="\n")

account_id|display|display_content_type|display_content_subject|display1
12345|123|Adult|Geography|321 

If the nested lists in this structure can have more than one item, you would have to describe how you want the multiple items to be output. (i.e. only the first one, multiply the lines repeating the other non-list values, ...)