After trying the solution offered by this thread:
What is the best way to call a Python script from another Python script?
I came along with another problem dealing with arguments.
I have:
test1.py
def some_func():
print 'in test 1, unproductive'
if __name__ == '__main__':
# test1.py executed as script
# do something
some_func()
service.py (with dummy arguments)
import argparse
import test1
actions = ['start', 'remove']
parser = argparse.ArgumentParser()
parser.add_argument("action", help="Possible actions are: "
"'{d[0]}|{d[1]}' ".format(d=actions))
parser.add_argument("-d", "--debug", help="Debug mode", action="store_true")
args = parser.parse_args()
def service_func():
print 'service func'
if __name__ == '__main__':
# service.py executed as script
# do something
service_func()
test1.some_func()
This works:
python service.py start
service func
in test 1, unproductive
However, if I want to add arguments in test1.py as well:
test1.py
import argparse
######## new stuff ##########
parser = argparse.ArgumentParser()
parser.add_argument("-d", "--debug", help="Debug mode", action="store_true")
args = parser.parse_args()
##############################
def some_func():
print 'in test 1, unproductive'
if __name__ == '__main__':
# test1.py executed as script
# do something
some_func()
Now I get:
python service.py start
usage: service.py [-h] [-d]
service.py: error: unrecognized arguments: start
Not sure why...
python service.py start - to argparse 'start' looks like a positional argument. It does not have a '--' to mark it as a flag string.
I'm guessing the parser in service.py is handling it ok, though you don't display or otherwise use the resulting args.
The usage in the error message is consistent with the parser in test1.py. It does not define a positional, just the --debug
usage: service.py [-h] [-d]
test1.py is using the same sys.argv list.
There are several solutions:
add a positional argument to test1
use parse_known_args instead of parse_args.
modify sys.argv in service.py (after parsing) to remove this 'start' string. A change in sys.argv in this script will carry over to test1. Print sys.argv in both to be sure.
use REMAINDER as documented in the docs
argparse.REMAINDER. All the remaining command-line arguments are gathered into a list. This is commonly useful for command line utilities that dispatch to other command line utilities:
Call
args, extras = parser.parse_known_args()
This would set
args to Namespace(debug=False) and extras to ['start']. Otherwise you get a tuple of these two values, (Namespace(debug=False), ['start']).
If you haven't modified sys.argv in the first script, the 2nd one will see the same list. Parsing does not modify this list.
Related
I have a small CLI app (myscript.py) that is defined like so.
import sys
import argparse
class MyParser(argparse.ArgumentParser):
'''
Overriden to show help on default.
'''
def error(self, message):
print(f'error: {message}')
self.print_help()
sys.exit(2)
def myfunc(args):
'''
Some function.
'''
print(args.input_int**2)
def main():
# Define Main Parser
main_par = MyParser(
prog='myapp',
description='main help')
# Define Command Parser
cmd_par = main_par.add_subparsers(
dest='command',
required=True)
# Add Subcommand Parser
subcmd_par = cmd_par.add_parser(
'subcmd',
description='subcmd help')
# Add Subcommand Argument
subcmd_par.add_argument(
'-i', '--input-int',
type=int,
help='some integer',
required=True)
# Add FromName Dispatcher
subcmd_par.set_defaults(
func=myfunc)
# Parse Arguments
args = main_par.parse_args()
# Call Method
args.func(args)
if __name__ == '__main__':
main()
The MyParser class simply overrides the error() method in argparse.ArgumentParser class to print help on error.
When I execute
$ python myscript.py
I see the default / main help. Expected.
When I execute
$ python myscript.py subcmd
I see the subcmd help. Expected.
When I execute
$ python myscript.py subcmd -i ClearlyWrongValue
I also see the subcmd help. Expected.
However, very annoyingly if I do the following
$ python myscript.py subcmd -i 2 --non-existent-argument WhateverValue
I see the default / main help and not subcmd help.
What can I do, to ensure that this last case shows me the subcmd help and not the main help? I thought the subparser structure would automatically procure the help from subcmd as found in the third case, but it is not so? Why?
The unrecognized args error is raised by parse_args
def parse_args(self, args=None, namespace=None):
args, argv = self.parse_known_args(args, namespace)
if argv:
msg = _('unrecognized arguments: %s')
self.error(msg % ' '.join(argv))
return args
The subparser is called via the cmd_par.__call__ with:
subnamespace, arg_strings = parser.parse_known_args(arg_strings, None)
for key, value in vars(subnamespace).items():
setattr(namespace, key, value)
if arg_strings:
vars(namespace).setdefault(_UNRECOGNIZED_ARGS_ATTR, [])
getattr(namespace, _UNRECOGNIZED_ARGS_ATTR).extend(arg_strings)
That is it is called with parse_known_args, and it's extras are returned to the main as UNRECOGNIZED. So it's the main than handles these, not the subparser.
In the $ python myscript.py subcmd -i ClearlyWrongValue case, the subparser raises a ArgumentError which is caught and converted into a self.error call.
Similarly, the newish exit_on_error parameter handles this kind of ArgumentError, but does not handle the urecognized error. There was some discussion of this in the bug/issues.
If you used parse_known_args, the extras would be ['--non-existent-argument', 'WhateverValue'], without distinguishing which parser initially classified them as such.
In the argparse module, is it possible (easily) to print/log arguments that have been changed from default values when running a script? For example,
my_script.py
argparse.add_argument("--arg1", default="val1")
argparse.add_argument("--arg2", default="val2")
Running:
python my_script.py --arg2 newval2
Print:
Arguments changed:
arg2 : newval2
Once you have parsed your arguments you can, take a look to this script:
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("-c", dest="c", default=1)
def main():
options = parser.parse_args()
print(options.c)
if __name__ == "__main__":
main()
If you save this code in a script tmp.py and then call:
$>python3 tmp.py
$>1
$>python3 tmp.py -c 12
$>12
I am able to pass command line arguments when running
python <filename>.py arg1
But when am trying to pass the command line arguments for running pytest it fails and gives error as below. Can you please advise.
pytest <filename>.py arg1
ERROR: file not found: arg1
EDIT:
For example am thinking of using it this way assuming I have passed an argument and am reading it via sys.argv:
import sys
arg = sys.argv[3]
def f():
return 3
def test_function():
assert f() == arg
Your pytest <filename>.py arg1 command is trying to call pytest on two modules <filename>.py and arg1 , But there is no module arg1.
If you want to pass some argument before running pytest then run the pytest from a python script after extracting your variable.
As others suggested though you would probably want to parameterize your tests in some other way, Try:Parameterized pytest.
# run.py
import pytest
import sys
def main():
# extract your arg here
print('Extracted arg is ==> %s' % sys.argv[2])
pytest.main([sys.argv[1]])
if __name__ == '__main__':
main()
call this using python run.py filename.py arg1
Here's the method I just cooked up from reading the parameterized pytest docs and hacking for a while... I don't know how stable or good it is going to be overall since I just got it working.
I did however check that HTML coverage generation works with this method.
add a file to your test directory for configuring the command-line args you want to pass:
tests\conftest.py
# this is just so we can pass --server and --port from the pytest command-line
def pytest_addoption(parser):
''' attaches optional cmd-line args to the pytest machinery '''
parser.addoption("--server", action="append", default=[], help="real server hostname/IP")
parser.addoption("--port", action="append", default=[], help="real server port number")
and then add a test file, with this special pytest_generate_tests function which is called when collecting a test function
tests\test_junk.py
def pytest_generate_tests(metafunc):
''' just to attach the cmd-line args to a test-class that needs them '''
server_from_cmd_line = metafunc.config.getoption("server")
port_from_cmd_line = metafunc.config.getoption("port")
print('command line passed for --server ({})'.format(server_from_cmd_line))
print('command line passed for --port ({})'.format(port_from_cmd_line))
# check if this function is in a test-class that needs the cmd-line args
if server_from_cmd_line and port_from_cmd_line and hasattr(metafunc.cls, 'real_server'):
# now set the cmd-line args to the test class
metafunc.cls.real_server = server_from_cmd_line[0]
metafunc.cls.real_port = int(port_from_cmd_line[0])
class TestServerCode(object):
''' test-class that might benefit from optional cmd-line args '''
real_server=None
real_port = None
def test_valid_string(self):
assert self.real_server!=None
assert self.real_port!=None
def test_other(self):
from mypackage import my_server_code
if self.real_server != None:
assert "couldn\'t find host" not in my_server_code.version(self.real_server, self.real_port)
then run (with HTML coverage, for example) with:
pytest tests\test_junk.py --server="abc" --port=123 --cov-report html --cov=mypackage
It seems monkeypatch also works.
Example:
import sys
def test_example(monkeypatch):
monkeypatch.setattr(sys, 'argv', ['/path/to/binary', 'opt1', '...'])
assert f() == '...'
def test_another():
# sys.argv is not modified here
assert f() != '...'
I have two python scripts with the following structure:
# Script1.py
from optparse import OptionParser
def main():
parser = OptionParser()
parser.add_option("-a", "--add-foobar", action="store_true", help="set foobar true",
dest="foobar", default=False)
options, args = parser.parse_args()
print options.foobar
if __name__ == "__main__":
main()
# Script2.py
from Script1 import main as script1Main
def main():
script1Main()
Is there a way to pass command line arguments from script 2 to script 1? Script 1 in this example is immutable, therefore this must be done only thorough optparse.
If you don't pass any arguments to parse_args, it just uses the value of sys.argv[1:], which is going to be whatever arguments were passed when you called Script2.py. The fact that Script2.py calls Script1.main doesn't change that.
Firstly, maybe use argparse instead. You can process all arguments in script 2, then pass the argument handle to script 1.
# Script1.py
def main(args):
print args
# Script2.py
import argparse
from Script1 import main as script1Main
def main():
parser = argparse.ArgumentParser(
parser.add_option("-a", "--add-foobar", action="store_true", help="set foobar true", default=False)
args = parser.parse_args()
script1Main(args)
if __name__ == "__main__":
main()
I have a unittest that wants to call an imported module to do both parse_os based on the unittest's command-line option but it seems unittest does not recognize the option, any ideas:
./python testParser.py --mac
option --mac not recognized
Usage: testParser.py [options] [test] [...]
Options:
-h, --help Show this message
-v, --verbose Verbose output
-q, --quiet Minimal output
-f, --failfast Stop on first failure
-c, --catch Catch control-C and display results
-b, --buffer Buffer stdout and stderr during test runs
Examples:
testParser.py - run default set of tests
testParser.py MyTestSuite - run suite 'MyTestSuite'
testParser.py MyTestCase.testSomething - run MyTestCase.testSomething
testParser.py MyTestCase - run all 'test*' test methods
in MyTestCase
I want to run my unittest program like this: python testParser.py --mac
EDITTED: Works now by changing 'unittest.main()' to:
runner = unittest.TextTestRunner(stream=stderr_file)
itersuite = unittest.TestLoader().loadTestsFromTestCase(TT28046_ForensicSearchSmokeTest)
runner.run(itersuite)
Unittest program:
import logging
import unittest
from myargparse import *
class MyTest(unittest.TestCase):
def test_parse_os(self):
## Parse the args:
self.install = install_sw(parse_os(arg=""))
print 'Which os? %s' % self.install
if __name__ == '__main__':
logging.basicConfig(level=logging.INFO)
# get the default logger
logger = logging.getLogger()
# add a file handler
logger.addHandler(logging.FileHandler('stdout.txt', mode='w'))
# set up a stream for all stderr output
stderr_file = open('stderr.txt', 'w')
# attach that stream to the testRunner
unittest.main(testRunner=unittest.TextTestRunner(stream=stderr_file))
My imported module:
import argparse
import os
import sys
def parse_os(arg):
my_os = ''
parser = argparse.ArgumentParser()
parser.add_argument("-m", "--mac",
action="store_true")
parser.add_argument("-w", "--win",
action="store_true")
args = parser.parse_args()
if args.mac:
print 'Mac'
my_os = "Mac"
if args.win:
print 'Windows'
my_os = "Windows"
return my_os
def install_sw(my_os):
installed_os = None
if my_os == 'Mac':
print 'Installing Mac...'
installed_os = 'Mac'
if my_os == 'Windows':
print 'Installing Windows...'
installed_os = 'Windows'
return installed_os
The sys.argv variable is a simple list so you can modify/replace it at your wish.
I'd consider using a context manager in this case, on the lines of:
class SysArgv(object):
def __init__(self, argv):
self._old_argv = sys.argv
sys.argv = argv
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, tb):
sys.argv = self._old_argv
return False
And used as:
In [4]: with SysArgv(['a', 'b', 'c']):
...: print(sys.argv)
...:
['a', 'b', 'c']
In your case simple wrap the test code like:
with SysArgv(['the_module_name.py', '--mac']):
# test code goes here
and the argparse module will see the arguments you wants.
As for passing the arguments to the unittest module when running the tests, it's possible passing the argv argument to unittest.main. From the documentation:
The `argv` argument can be a list of options passed to the program, with the first element being the program name. If not specified or `None`, the values of `sys.argv` are used.
However in this case you should modify the sys.argv variable before calling unittest.main:
if __name__ == '__main__':
options = ['name_of_module.py'] + sys.argv[-1:] # last argument as option for the test
with SysArgv(sys.argv[:-1]): # or modify how you want
unittest.main(argv=options)
Have you tried using just '-m' instead of '--mac'?
You may also try:
import optparse
parser = optparse.OptionParser()
parser.add_option("-m", "--mac",
dest="mac",
action="store_true",
help="Run as Mac")
parser.add_option("-w", "--win",
dest="win",
action="store_true",
help="Run as Win")
(options, args) = parser.parse_args()
Thank you all for your suggestions but I decided to go with this to limit the changes to my program.
Instead of calling 'unittest.main()', I just changed to call the following:
runner = unittest.TextTestRunner(stream=stderr_file)
itersuite = unittest.TestLoader().loadTestsFromTestCase(MyTest)
runner.run(itersuite)
Based on all the answers here, I originally did this simple hack, and it worked:
# Change sys.argv before unittest tries to parse our args
sys.argv = [sys.argv[0]] # Replace with only the first arg
unittest.main()
The I realized I could still use all the unitest command line args, and in my case I was just passing a bunch of paths, so anything starting with a "-" could just be passed on and there is no need to hack anything since unittest.main() has an argv argument
# Pass on options, and more importantly, don't pass on ALL args
options = [sys.argv[0]] + [a for a in sys.argv if a.startswith("-")]
unittest.main(argv=options)
Just filter out all argparse and not arparse parameters and send then ones not being argparse arguments to sys.argv which is the one unittest uses:
args, notknownargs = parser.parse_known_args()
sys.argv[1:] = notknownargs