python中来自yaml的csv文件

Question

4:
- a: [0.6511928334730416, -0.6444996859128429, 0.40070930065859994]
  b: [-70.26386506067132, 19.563101216582368, 315.91419304402643]
  c: [462, 429, 401, 389]
  d: 1
5:
- e: [0.6511928334730416, -0.6444996859128429, 0.40070930065859994]
  f: [-70.26386506067132, 19.563101216582368, 315.91419304402643]
  g: [462, 429, 401, 389]
  h: 1

This is my yml format and I have to extract only the values of key c and g from it and create a csv file. I am new to python.
Can anyone guide me here thanks in advance

Answer 1

Through looping you can do but this is just an idea you can have better also

try this:-

import yaml
MyDict = yaml.load(open('example.yaml'))

    key = ['c','g']
    for i in MyDict.values():
        for j  in i:
            for k in key:
                if k in j:
                    print(j.get(k))

Answer 2

If your yaml converted to dict is similar to this :

d = {4:
       {
      'a': [0.6511928334730416, -0.6444996859128429, 0.40070930065859994],
      'b': [-70.26386506067132, 19.563101216582368, 315.91419304402643],
      'c': [462, 429, 401, 389],
      'd': 1
       },
    5:
     {'e': [0.6511928334730416, -0.6444996859128429, 0.40070930065859994],
      'f': [-70.26386506067132, 19.563101216582368, 315.91419304402643],
      'g': [462, 429, 401, 380],
      'h': 1
     }
    }

The following code you can try to convert the values to CSV :

import csv  
import itertools  

# taking only the values of keys 'c' and 'g'
li = [i[j] for i in d.values()  for j in i.keys()  if j == "c" or j == "g"]

# the above list of list making a flat list for better result
merged = list(itertools.chain.from_iterable(li))

with open("filename.csv",'w') as myfile:
    wr = csv.writer(myfile, lineterminator='\n')
    # If you want first list to csv you can use li instead of merged 
    wr.writerow(merged)

Answer 3

I have tried and tested this

import yaml

with open(r'test.yaml') as file:
    documents = yaml.full_load(file)

for item, doc in documents.items():
    print(item, ":", doc)