"Unhashable type: list"

[prasadhegde]

Method_A expects parameters in the below standard. The final argument, arg3, accepts one or more values
Method_A(arg1 , arg2, arg3)

I have a list which contains the below data

my_list[0] = "hello"
my_list[1] = "world"

Method_A works fine when I pass arguments in the below fashion

Method_A(arg1, arg2, my_list[0], my_list[1])

But, when i pass the entire list to method_A,

Method_A("", "", my_list)

I observe "Unhashable type: list" as error.

Any suggestions?

[buran]

lists are mutable, thus not hashable. Make my_list tuple.

[prasadhegde]

i tried converting to tuple, does not work still

Just to explain further,

arg[0] = "10"
arg[1] = "20"
arg[2] = "30"

when i pass these values individually to my method, the function works fine
Ex : Method(arg[0], arg[1], arg[2])

But when is send the list as argument, i see "Unhashable type: List"
Ex: Method(arg)

[buran]

post your actual code. if you converted the list to tuple why do you still get unhashable type list error?

[buran]

it's difficult to tell from information provided, but you may need to unpack your list.
e.g. method(*arg)

[prasadhegde]

*******python_file1.py***********
in this python_file1, i am setting up data to invoke main method present in python_file2

......
node_id = get_node_id(node)

test_case[0] = "some_value0"
test_case[1] = "some_value1"
test_case[2] = "some_value2"

===> Invoking main method
python_file2.main(["h","--node-id="+ node_id, "run", test_case[0], test_case[1], test_case[2], "--force"])
THis call to main method works absolutely fine. But when i pass the complete list or convert it into a tuple and pass it to main, i see Unhashable error

python_file2.main(["h","--node-id="+ node_id, "run", test_case, "--force"] ===> error



**********python_file2.py************
def main(argv):
parser = argparse.ArgumentParser
parser.add_argument("-C", metavar="PATH")
parser.add_argument("--node-id", metavar="stb-tester-abcdef123456")
subcommands = parser.add_subparsers(
dest="command", title="COMMANDS", metavar="COMMAND",
description=dedent("""\
Note: Run "./stbt_rig.py COMMAND -h" to see the additional
parameters for each COMMAND."""))
run_parser = subcommands.add_parser("run", help="Run test-cases")
run_parser.add_argument("test_cases", nargs='+', metavar="TESTCASE")
run_parser.add_argument("--force", action="store_true")

args = parser.parse_args(argv[1:])
......

[buran]

node_id = get_node_id(node)
node_cmd = "--node-id={}".format(node_id)
test_case = ["some_value0", "some_value1", "some_value2"]
cmd = ["h", node_cmd, "run"]
cmd.extend(test_case)
cmd.append("--force")
print cmd
python_file2.main(cmd)

something like this. other options are also possible

[prasadhegde]

Wow ! That worked !!! Thank you :)

[buran]

something I don't like, but would so work

python_file2.main(["h","--node-id="+ node_id, "run"] + test_case + ["--force"])