Question

new one for me — I’m assuming this is fairly easy, but I’ve never worked with arrays before, so I’m curious as to how it works.

I have a dict of dicts, like so:

{'bob': {'a':1, 'b':2, ...}, 'joe': {'a':2, 'c':3, ...} ...}

I’d like to turn it into an array so I can write it to a CSV and then turn it into a heatmap using R. I was trying to cheat and just write each nested dict to an individual row, but of course that won’t work because not every key is present in every nested dict. simple, right?

desired output would look like (in tabular form):

,a,b,c
bob,1,2,0
joe,2,0,3

Answer 1

If your columns are fixed, you could simply do something like:

cols = ['a', 'b', 'c']
csv.writerow([''] + cols)
for name, values in data.iteritems():
    csv.writerow([name] + [values.get(c, 0) for c in cols])