4 ms·

Perhaps it could trigger if you do function(*iterable), with a huge iterable?

• drizze 9y ago
  I think *iterable would just pass one argument that's a list, not pass each argument individually
  • fiddlerwoaroof 9y ago
    >>> print([1,2,3]) [1,2,3] >>> print(*[1,2,3]) 1 2 3
    • aisofteng 9y ago
      That doesn't tell you anything about when the list is expanded.
  • dragonwriter 9y ago
    The asterisk at the call site (where it turns an iterable into multiple passed arguments) not the function definition site (where it collects otherwise unconsumed arguments into a single list.)
  • orf 9y ago
    There may be some optimization at the interpreter level, but it appears to Python that each element of 'iterable' is passed as an individual argument
• winterlight 9y ago
  Nope, that works just fine. >>> def f(*x): print(x[-1]) >>> f(range(300)) 299 And surprisingly, in python 2.7, I was able to define a function that takes more than 255 arguments. But perhaps this only worked because I cheated and used exec. >>> exec("def f(" + ",".join("f" + str(x) for x in range(300)) + "): print(f299)" >>> f(*range(300)) 299
  • qquark 9y ago
    Interestingly enough, the function def (the exec part) does not work in 3.6, as one could expect, but in 2.7 even though the function definition works, you can make the call fail by generating actual parameters: >>> exec("def f(" + ",".join("f" + str(x) for x in range(300)) + "): print(f299)") >>> f(*range(300)) 299 >>> exec("f(" + ", ".join(str(i) for i in range(300)) + ")") Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<string>", line 1 SyntaxError: more than 255 arguments When reducing the number of parameters to be invalid for f, the following error is shown: >>> exec("f(" + ", ".join(str(i) for i in range(30)) + ")") Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<string>", line 1, in <module> TypeError: f() takes exactly 300 arguments (30 given) Which seems a bit paradoxical - "You need 300 arguments" - "No, wait, actually, you can't have more than 255" ... ;) It looks like they either had changed the internals of python 3, making it fail at the definition as a side effect instead of when calling, or used the same underlying logic but purposely chose to issue the exception to potentially catch the problem earlier...
• Waterluvian 9y ago
  I believe args and *kwargs have special opcodes already.