# the one and only Dev.E.L'Peer  https://github.com/develpeer
##
# This gist explores function invocation, positional and keyword params 
##
from random import randint


def standard_arg(arg):
    print(arg)


def pos_only_arg(arg, /):
    print(arg)


def kwd_only_arg(*, x):
    print(x)


def combined_example(pos_only, /, standard, *, kwd_only):
    print(f"pos_only:{pos_only}, standard:{standard}, kwd_only:{kwd_only}")


try:
    pos_only_arg(x=7)
except Exception as e:
    print(f"This should not work, since anything preceeding / is a positional argument[{e}]")

try:
    kwd_only_arg(7, x=7)
except Exception as e:
    print(f"This should not work, since anything following * is a kwarg [{e}]")

# either of these work
combined_example(1, 2, kwd_only=3)
combined_example(1, standard=2, kwd_only=3)

try:
    combined_example(pos_only=1, standard=2, kwd_only=3)
except Exception as e:
    print(f"This should not work: [{e}]")


def name_collision(name, **kwds):
    print(f"Value of name is '{name}'")
    print(f"Value of name in kwds is '{kwds.get('name')}'")


name_collision("Dev")
name_collision(name="Loper")
try:
    name_collision("Dev", name="Loper")
except Exception as e:
    print(f"If the name occurs in both pos and kwarg, that will throw an error:[{e}]")


# workaround for above
def duplicate_arguments_2(name, /, **kwds):
    print(f"Value of name is '{name}'")
    print(f"Value of name in kwds is '{kwds.get('name')}'")


duplicate_arguments_2("Dev", **{'name': "ELoper"})
# or..
duplicate_arguments_2("Dev", name="ELoper")


def is_the_last_argument_a_positional_argument(p1, *pos_args, p2):
    for p in pos_args:
        print(f"Arg:{p}")
    print("pos_arg:", p2)


try:
    is_the_last_argument_a_positional_argument(1, 2)
except Exception as e:
    print(f"Python will treat anything after 'variadic' as keyword args:[{e}]")

# however this should work
is_the_last_argument_a_positional_argument(1, 2, p2="200")

# "one" expresion can be nested etc..But wont allow match, if statements (except ternaries)
f = lambda x, y, z: x + y if (True if z else randint(0, 1)) else x * y
print(f(1, 2, True))
print(f(1, 2, False))


def f2(a,b):
    print(f"a={a},b={b}")

f2(1,2)
l = (1,2)
f2(*l)
f2(1,*(2,))
#positional parameters are applied before keyword params 
try:
    f2(a=1,*(2,))
except TypeError:
    print("positional parameters are applied before keyword params ")
f2(b=2,*(1,))