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How can I programmatically access the default argument values of a method in Python? For example, in the following
def test(arg1='Foo'):
pass
how can I access the string 'Foo' inside test?
229
Python has a different way of representing syntax and default values for function arguments. Default values indicate that the function argument will take that value if no argument value is passed during the function call. The default value is assigned by using the assignment(=) operator of the form keywordname=value.
Default argument is fallback value In Python, a default parameter is defined with a fallback value as a default argument. Such parameters are optional during a function call. If no argument is provided, the default value is used, and if an argument is provided, it will overwrite the default value.
A default argument is a value provided in a function declaration that is automatically assigned by the compiler if the calling function doesn't provide a value for the argument.
To access command-line arguments from within a Python program, first import the sys package. You can then refer to the full set of command-line arguments, including the function name itself, by referring to a list named argv. In either case, argv refers to a list of command-line arguments, all stored as strings.
They are stored in test.func_defaults (python 2) and in test.__defaults__ (python 3).
As @Friedrich reminds me, Python 3 has "keyword only" arguments, and for those the defaults are stored in function.__kwdefaults__
164
Consider:
def test(arg1='Foo'):
pass
In [48]: test.func_defaults
Out[48]: ('Foo',)
.func_defaults gives you the default values, as a sequence, in order that the arguments appear in your code.
Apparently, func_defaults may have been removed in python 3.
39
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