How to find a key's value from a list of dictionaries?

Question

How do I get a given key's value from a list of dictionaries?

mylist = [
    {
      'powerpoint_color': 'blue',
      'client_name': 'Sport Parents (Regrouped)'
    },
    {
      'sort_order': 'ascending',
      'chart_layout': '1',
      'chart_type': 'bar'
    }
]

The number of dictionaries in mylist is unknown and I want to find the value attached to the key 'sort_order'.

My failed attempt:

for key in mylist:
    for value in key:
        print(key['sort_order'])

Answer 1

mylist= [{'powerpoint_color': 'blue', 'client_name': 'Sport Parents (Regrouped)'}, {'sort_order': 'ascending', 'chart_layout': '1', 'chart_type': 'bar'}]

print [d["sort_order"] for d in mylist if "sort_order" in d][0]

Result:

ascending

---

You could also combine all of the dictionaries into a single dict, and access that:

combined_d = {key: value for d in mylist for key,value in d.iteritems() }
print combined_d["sort_order"]

Answer 2

You can get it using this code:

for d in mylist:
    if 'sort_order' in d:
        print(d['sort_order'])

First you iterate over list, for each dictionary check if it has needed key and if it does get value.

Answer 3

Something like that ?

for hash in mylist:
    if "sort_order" in hash: print hash ["sort_order"]

Answer 4

While not as readable, this version:

• provides short-circuiting
• avoids a double lookup

---

print reduce( lambda a,b: a or b, (l.get("sort_order") for l in mylist) )

Note that this would fail if some of your keys evaluated to false, but it's not hard to develop a version that doesn't from this starting point