YAML load for chained file handles

Question

PyYAML makes loading a .yml document trivial.

config = yaml.load(open('myconfig.yml', 'r'))

I have a list of YAML file names filelist, and I'm trying to come up with a concise Pythonic way of loading them together (treating them as a single document). This is what I tried.

fhlist = [open(filename, 'r') for filename in filelist]
cfginput = itertools.chain(*fhlist)
config = yaml.load(cfginput)

However, this is causing an exception.

AttributeError: 'itertools.chain' object has no attribute 'read'

What am I doing wrong? Is there a simple solution to the task I'm trying to accomplish?

Answer 1

I assume loading them together means either read them all, or merging them:

Read them all

yamls = []
for filename in filelist:
    with open(filename) as f:
        yamls.append(yaml.load(f))

Merge them all

yamls = {}
for filename in filelist:
    with open(filename) as f:
        yamls.update(yaml.load(f))

Notice: This will overwrite properties with same keys, and is not recursive.

Edit: If you want to concat all files and read them after as yaml:

content = ''
for filename in filelist:
    with open(filename) as f:
        content += f.read()
result = yaml.load(content)

This will probably get the same result as merging the yaml dicts...