0904 self-summary
* Function usage
def fn(a, b, c, *, d=0, x):
print(a)
print(b)
print(c)
print(d)
print(x)
fn(10, 20, 30, x=30, d=100)Where * is the equivalent effect of a boundary, it is in front of the location parameter, followed by the key parameter
*Before positional parameters are: the location must be assigned no value, location may not have a value assigned, no value must be in position after*After all keyword arguments: the keyword must be assigned no value, do not have value keywords can be assigned parameters are passed by name, so any order*It can be followed by a variable to receive all of the positional parameters incompletely received