XPartial Docs¶
Library that eXtends functools.partial to allow for selective argument freezing.
Skip positional arguments one by one, assign from the end of the argument list, overwrite frozen arguments with kwargs, and make use of default values in middle of your function calls.
Quickstart:
from xpartial import xpartial, Skip, SkipRest
# Same as: xpartial(range, stop=5)
f = xpartial(range, Skip, 6) # 'Skip' skips a single positional arg
f(2) # -> 2, 3, 4, 5
f(1, 2) # -> 1, 3, 5
foo = lambda a, b, c=0, d=0, e=0: (a, b, c, d, e) # takes+returns 5 args
g = xpartial(foo, 10, SkipRest, 40, 50) # 'SkipRest' greedily skips args
g(20, 30) # -> 10, 20, 30, 40, 50
g(20) # -> 10, 20, 0, 40, 50
bar = lambda a=3, b=5, *args: (a, b, *args)
h = xxpartial({...}, 15) # alternative syntax: ...=Skip, {...}=SkipRest
h(1, 2, 3) # -> 1, 2, 3, 15 (frozen args are in the very end)
h() # -> 3, 5, 15 (default values are applied)
h(Skip, 42, 1337) # -> 3, 42, 1337, 15 (Skips here use default values)
- xpartial.xpartial(func: Callable[[...], xpartial.R], /, *args: Any, **kwargs: Any) Callable[[...], xpartial.R]¶
Return a new function with partially frozen arguments.
An eXtended partial utility function that allows you to selectively freeze any parameters with specified values, creating a partial function. Frozen arguments in partial functions can be overwritten through keyword arguments. Function xpartialmethod behaves just like xpartial, but is instead used for method definitions.
- Parameters
func – Target function to apply arguments to.
args – Positional arguments to be frozen.
kwargs – Keyword arguments to be frozen.
- Returns
Partial function with frozen arguments.
- xpartial.xpartialmethod() NoReturn¶
Return a new method with partially frozen arguments.
An eXtra eXtended partial function with syntactic sugar for convenience when writing simple partials. Skip and SkipRest can be optionally replaced with … and {…}, respectively. Not recommended for dynamically created partial functions that accept Ellipsis or set(Ellipsis) arguments.
- class xpartial.Skip(*args: Any, **kwargs: Any)¶
Skip a single positional argument.
When used as argument for xpartial, this constant skips over a single positional argument of the target function, requiring said argument to be later provided to the partial function. When used as an argument for a partial function created by xpartial, the argument is set to its default value (if there isn’t one, an error is thrown).
- class xpartial.SkipRest(*args: Any, **kwargs: Any)¶
Skip as many positional arguments as possible, allowing one to freeze arguments at the end of the function.
When used as an argument for xpartial, skips as many arguments as possible, leaving the remaining frozen arguments and Skips to the end of the argument list. Only the first SkipRest provided xpartial has an effect, the rest are ignored entirely. Unlike Skip, SkipRest can’t be used in partial function calls.