pythonamazon-web-servicesaws-ecr

argument errors when using using Python to access to aws ecr


here is the function:

def sh(*command, read_output=False, **kwargs):
    command_text = " ".join(command)
    print(f"\t> {command_text}")
    try:
        if read_output:
            return check_output(command, **kwargs).decode("utf8")
        else:
            check_call(command, **kwargs)
    except CalledProcessError as failure:
        print(
            f'ERROR: "{command_text}" command reported failure! Return code {failure.returncode}.'
        )
        sys.exit(failure.returncode)

I'm trying to use this function to get aws erc get-login first, then use that returned login command to login to aws erc. here is my codes:

result = sh('aws', 'ecr', 'get-login', '--no-include-email', read_output=True)
re = result.split()
sh(re)

then I get error:

command_text = " ".join(command)
TypeError: sequence item 0: expected str instance, list found

I think the sh function expect arguments something like `('docker', 'login', '-u', 'AWS', '-p'...), but how can I achieve this?


Solution

  • You can use * to unpack list/tuple and function get it as many arguments

    sh( *re )
    

    Or you can remove * from *command in definiton

    def sh(command, ...)
    

    and then you can send it only as list/tuple

    sh( re )
    

    but you can also check if command is list or string

    if isinstance(command, str): 
        command_text = command 
    elif isinstance(command, list, tuple): 
        command_text = " ".join(command)
    

    so then you can send it directly as one string.

    sh( 'aws ecr get-login --no-include-email' )
    

    or list with strings

    sh( ['aws', 'ecr', 'get-login', '--no-include-email'] )
    

    BTW: Similar way works ** with dictionary and named arguments

    def fun(a=0, b=0, c=0):
        print('a:', a)
        print('b:', b)
        print('c:', c)
    
    data = {'b':2}
    
    fun(**data)