How to get values from list of dictionary in python?

Question

I'm trying to get the values from a specific element and append them as a single list.

Input:

X = [
    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Action": [
                    "iam:CreateInstanceProfile",
                    "iam:DeleteInstanceProfile",
                    "iam:GetRole",
                    "iam:GetInstanceProfile",
                    "iam:GetPolicy",
                    "iam:ListGroupPolicies",
                    "iam:RemoveRoleFromInstanceProfile",
                    "iam:CreateRole",
                    "iam:DeleteRole",
                    "iam:PutRolePolicy",
                    "iam:ListInstanceProfiles",
                    "iam:GetGroup",
                    "iam:AddRoleToInstanceProfile",
                    "iam:PassRole",
                    "iam:GetUserPolicy",
                    "iam:DeleteRolePolicy",
                    "iam:UpdateRole",
                    "iam:GetGroupPolicy",
                    "iam:GetUser",
                    "iam:ListRolePolicies",
                    "iam:GetRolePolicy",
                ],
                "Resource": [
                    "arn:aws:iam::*:policy/*",
                    "arn:aws:iam::*:instance-profile/*",
                    "arn:aws:iam::*:user/*",
                    "arn:aws:iam::*:role/*",
                    "arn:aws:iam::*:group/*",
                ],
                "Effect": "Allow",
                "Sid": "VisualEditor0",
            },
            {
                "Action": ["iam:ListPolicies", "iam:ListRoles", "iam:ListGroups"],
                "Resource": "*",
                "Effect": "Allow",
                "Sid": "VisualEditor1",
            },
        ],
    }
]

Expected Output:

Y = [
    "iam:CreateInstanceProfile",
    "iam:DeleteInstanceProfile",
    "iam:GetRole",
    "iam:GetInstanceProfile",
    "iam:GetPolicy",
    "iam:ListGroupPolicies",
    "iam:RemoveRoleFromInstanceProfile",
    "iam:CreateRole",
    "iam:DeleteRole",
    "iam:PutRolePolicy",
    "iam:ListInstanceProfiles",
    "iam:GetGroup",
    "iam:AddRoleToInstanceProfile",
    "iam:PassRole",
    "iam:GetUserPolicy",
    "iam:DeleteRolePolicy",
    "iam:UpdateRole",
    "iam:GetGroupPolicy",
    "iam:GetUser",
    "iam:ListRolePolicies",
    "iam:GetRolePolicy",
    "iam:ListPolicies",
    "iam:ListRoles",
    "iam:ListGroups",
]

Here I'm trying to get the values of all the 'Action' and store them as a single list. How can I do that?

Thanks in advance.

Answer 1

Try:

Y = [j for i in [i['Action'] for i in X[0]['Statement']] for j in i]

Now you can print it via:

print(Y)

Note that it is recommended not to use lower cases in python while naming variables.

---

If you don't like Ultra-One-Liners, try:

Y = []
for i in [i['Action'] for i in X[0]['Statement']]:
    Y.append(j for j in i)

---

If you never liked One-Liners:

Y = []
for i in X[0]['Statement']:
    for j in i['Action']:
        Y.append(j)

Explanation on the one-liner:

• First it find out i , which is all the Action s in your X .
• Then it finds j , which is the each element in the i .

---

Here:

X = [
    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Action": [
                    "iam:CreateInstanceProfile",
                    "iam:DeleteInstanceProfile",
                    "iam:GetRole",
                    "iam:GetInstanceProfile",
                    "iam:GetPolicy",
                    "iam:ListGroupPolicies",
                    "iam:RemoveRoleFromInstanceProfile",
                    "iam:CreateRole",
                    "iam:DeleteRole",
                    "iam:PutRolePolicy",
                    "iam:ListInstanceProfiles",
                    "iam:GetGroup",
                    "iam:AddRoleToInstanceProfile",
                    "iam:PassRole",
                    "iam:GetUserPolicy",
                    "iam:DeleteRolePolicy",
                    "iam:UpdateRole",
                    "iam:GetGroupPolicy",
                    "iam:GetUser",
                    "iam:ListRolePolicies",
                    "iam:GetRolePolicy",
                ],
                "Resource": [
                    "arn:aws:iam::*:policy/*",
                    "arn:aws:iam::*:instance-profile/*",
                    "arn:aws:iam::*:user/*",
                    "arn:aws:iam::*:role/*",
                    "arn:aws:iam::*:group/*",
                ],
                "Effect": "Allow",
                "Sid": "VisualEditor0",
            },
            {
                "Action": ["iam:ListPolicies", "iam:ListRoles", "iam:ListGroups"],
                "Resource": "*",
                "Effect": "Allow",
                "Sid": "VisualEditor1",
            },
        ],
    }
]

Answer 2

A simple, neat generator function:

def get_all_actions(documents):
    for doc in documents:
        for stmt in doc.get("Statement", []):
            yield from stmt.get("Action", [])

Using your input:

>>> print(list(get_all_actions(X)))
['iam:CreateInstanceProfile', 'iam:DeleteInstanceProfile', 'iam:GetRole', 'iam:GetInstanceProfile', 'iam:GetPolicy', 'iam:ListGroupPolicies', 'iam:RemoveRoleFromInstanceProfile', 'iam:CreateRole', 'iam:DeleteRole', 'iam:PutRolePolicy', 'iam:ListInstanceProfiles', 'iam:GetGroup', 'iam:AddRoleToInstanceProfile', 'iam:PassRole', 'iam:GetUserPolicy', 'iam:DeleteRolePolicy', 'iam:UpdateRole', 'iam:GetGroupPolicy', 'iam:GetUser', 'iam:ListRolePolicies', 'iam:GetRolePolicy', 'iam:ListPolicies', 'iam:ListRoles', 'iam:ListGroups']
>>>

Answer 3

Y=X[0]['Statement'][0]['Action']