There is no way to get argparse to do this for you. However, you can make argparse accept any number of positional arguments: parser.add_argument(‘FILES’,nargs=”*”) options=parser.parse_args() file1,optional_files=options.FILES[0],options.FILES[1:] Of course, you may want to add some checks to make sure that at least 1 file was given, etc. EDIT I’m still not 100% sure what you want … Read more
You need to use named parameters, like so: myfunc(a, c:5);
Although not mentioned in glibc documentation or getopt man page, optional arguments to long style command line parameters require ‘equals sign’ (=). Space separating the optional argument from the parameter does not work. An example run with the test code: $ ./respond –praise John Kudos to John $ ./respond –praise=John Kudos to John $ ./respond … Read more
Use IsMissing: If IsMissing(arg) Then MsgBox “Parameter arg not passed” End If However, if I remember correctly, this doesn’t work when giving a default for the argument, and in any case it makes using the default argument rather redundant.
Here is an example of passing mode as optional parameter void myfunc(int blah, int mode = 0) { if (mode == 0) do_something(); else do_something_else(); } you can call myfunc in both ways and both are valid myfunc(10); // Mode will be set to default 0 myfunc(10, 1); // Mode will be set to 1
Example from the guide: \newcommand{\example}[2][YYY]{Mandatory arg: #2; Optional arg: #1.} This defines \example to be a command with two arguments, referred to as #1 and #2 in the {<definition>}–nothing new so far. But by adding a second optional argument to this \newcommand (the [YYY]) the first argument (#1) of the newly defined command \example is … Read more
Let’s look at an example: def f(value, key, hash={}): hash[value] = key return hash print(f(‘a’, 1)) print(f(‘b’, 2)) Which you probably expect to output: {‘a’: 1} {‘b’: 2} But actually outputs: {‘a’: 1} {‘a’: 1, ‘b’: 2}
No. A workaround is to overload with another method that doesn’t have out / ref parameters, and which just calls your current method. public bool SomeMethod(out string input) { … } // new overload public bool SomeMethod() { string temp; return SomeMethod(out temp); } If you have C# 7.0, you can simplify: // new overload … Read more
Python 3.7 Use the defaults parameter. >>> from collections import namedtuple >>> fields = (‘val’, ‘left’, ‘right’) >>> Node = namedtuple(‘Node’, fields, defaults=(None,) * len(fields)) >>> Node() Node(val=None, left=None, right=None) Or better yet, use the new dataclasses library, which is much nicer than namedtuple. >>> from dataclasses import dataclass >>> from typing import Any >>> … Read more