Can I get a list of profiles that are currently defined by the aws command?

It is slightly different from getting the list, but it refers to what is defined in the input complement of the aws command installed with pip.
After the --profile option, you can save it in Tab to see the profile name defined as follows:

$awsec2describe-instances --profile 
 default prof1 prof2
 $

Credentials currently configured in some way, such as aws configure or AWS_DEFAULT_PROFILE, can be found in the following commands:

$awssts get-caller-identity
{
    "Account": "*****", 
    "UserId": "*****", 
    "Arn": "arn:aws:iam::****"
}

You can check the contents of the configuration file by using the following command:
Among them is a list of currently configured profiles.

cat to /.aws/credentials

AWS has the configuration and credentials files.Some profiles are written only in the configuration file through /.aws/config, while others are written only in the credentials file through /.aws/credentials.

You can also use the environment variable. You can also use AWS_CONFIG_FILE or AWS_SHARED_CREMENTALS_FILE to switch to another configuration or credentials file.

Therefore, looking only at through /.aws/credentials may not solve the problem.

As suggested by ksaito

$aws --profile 
 default prof1 prof2

The output is a complementary candidate, so you can get a list of questions by directly executing the complementary command.Specifically

$env COMP_LINE='aws --profile'aws_completer
default
prof1
prof2

I wonder if it looks like this.(env doesn't matter.)