flatten nested dict values in a list in Python 3 - python-3.x

Question

I've got this data structure coming from Vimeo API
{'duration': 720,
'language': 'sv',
'link': 'https://vimeo.com/neweuropefilmsale/incidentbyabank',
'name': 'INCIDENT BY A BANK',
'user': {
'link': 'https://vimeo.com/neweuropefilmsales',
'location': 'Warsaw, Poland',
'name': 'New Europe Film Sales'
}
}
I want to transofrm in
[720, "sv", "http..", "incident.." "http..", "Warsaw", "New Europe.."]
to load it in a Google spreadsheet. I also need to maintain consistence values order.
PS. I see similar questions but answers are not in Python 3
Thanks

Answer 1

I'm going to use the csv module to create a CSV file like you've described out of your data.
First, we should use a header row for your file, so the order doesn't matter, only dict keys do:
import csv
# This defines the order they'll show up in final file
fieldnames = [
'name', 'link', 'duration', 'language',
'user_name', 'user_link', 'user_location',
]
# Open the file with Python
with open('my_file.csv', 'w', newline='') as my_file:
# Attach a CSV writer to the file with the desired fieldnames
writer = csv.DictWriter(my_file, fieldnames)
# Write the header row
writer.writeheader()
Notice the DictWriter, this will allow us to write dicts based on their keys instead of the order (dicts are unordered pre-3.6). The above code will end up with a file like this:
name;link;duration;language;user_name;user_link;user_location
Which we can then add rows to, but let's convert your data first, so the keys match the above field names:
data = {
'duration': 720,
'language': 'sv',
'link': 'https://vimeo.com/neweuropefilmsale/incidentbyabank',
'name': 'INCIDENT BY A BANK',
'user': {
'link': 'https://vimeo.com/neweuropefilmsales',
'location': 'Warsaw, Poland',
'name': 'New Europe Film Sales'
}
}
for key, value in data['user'].items():
data['user_{}'.format(key)] = value
del data['user']
This ends up with the data dictionary like this:
data = {
'duration': 720,
'language': 'sv',
'link': 'https://vimeo.com/neweuropefilmsale/incidentbyabank',
'name': 'INCIDENT BY A BANK',
'user_link': 'https://vimeo.com/neweuropefilmsales',
'user_location': 'Warsaw, Poland',
'user_name': 'New Europe Film Sales',
}
We can now simply insert this as a whole row to the CSV writer, and everything else is done automatically:
# Using the same writer from above, insert the data from above
writer.writerow(data)
That's it, now just import this into your Google spreadsheets :)

Answer 2

This is a simple solution using recursion:
dictionary = {
'duration': 720,
'language': 'sv',
'link': 'https://vimeo.com/neweuropefilmsale/incidentbyabank',
'name': 'INCIDENT BY A BANK',
'user': {
'link': 'https://vimeo.com/neweuropefilmsales',
'location': 'Warsaw, Poland',
'name': 'New Europe Film Sales'
}
}
def flatten(current: dict, result: list=[]):
if isinstance(current, dict):
for key in current:
flatten(current[key], result)
else:
result.append(current)
return result
result = flatten(dictionary)
print(result)
Explanation: We call flatten() until we reach a value of the dictionary, that is not a dictionary itself (if isinstance(current, dict):). If we reach this value, we append it to our result list. It will work for any number of nested dictionaries.
See: How would I flatten a nested dictionary in Python 3?
I used the same solution, but I've changed the result collection to be a list.