elegant way to reduce a list of dictionaries?

Question

I have a list of dictionaries and each dictionary contains exactly the same keys. I want to find the average value for each key and I would like to know how to do it using r

Answer 1

As an alternative, if you're going to be doing such calculations on data, then you may wish to use pandas (which will be overkill for a one off, but will greatly simplify such tasks...)

import pandas as pd

data = [
  {
    "accuracy": 0.78,
    "f_measure": 0.8169374016795885,
    "precision": 0.8192088044235794,
    "recall": 0.8172222222222223
  },
  {
    "accuracy": 0.77,
    "f_measure": 0.8159133315763016,
    "precision": 0.8174754717495807,
    "recall": 0.8161111111111111
  },
  {
    "accuracy": 0.82,
    "f_measure": 0.8226353934130455,
    "precision": 0.8238175920455686,
    "recall": 0.8227777777777778
  }, # ...
]

result = pd.DataFrame.from_records(data).mean().to_dict()

Which gives you:

{'accuracy': 0.79000000000000004,
 'f_measure': 0.8184953755563118,
 'precision': 0.82016728940624295,
 'recall': 0.81870370370370382}