Regular Expressions: Search in array list

I want to filter strings in a list based on a regular expression. I tried defining as variable ${TagValue} but it gives null value or an empty list:

Bascially i want to list down those instances that have Environment tag is equal to the "Tag Value":

Here's my code:

TagValue = ['DEV', 'DEVDR', 'QA','TEST', 'SND', 'STG', 'sit', 'sandbox', 'Development', 'NonProd', 'NON-PROD']
instance_list = []
Instances = ec2_resource.instances.all()
for each in Instances:
    instance_list.append(each.id) # count total # of instances including all env tags 
        
for i in instance_list:
    ins_res = ec2_resource.Instance(i)
    ins_tag = ins_res.tags
    ins_state = ins_res.state
    if ins_state['Name']=='running':
        for item in ins_tag:
            if item['Key'] == 'Environment':
                val = item['Value']
                pattern = re.compile(r'\b${tag_value}\w*', re.IGNORECASE)
                print(re.findall(pattern,val)) 

Output is:

[]
[]
[]
.....