All examples tested using Python 3.13.2 on Windows 10.
When calling range(), I must use positional arguments, or otherwise I get an exception.
>>> range(2, 5)
range(2, 5)
>>> range(start=2, stop=5)
Traceback (most recent call last):
File "<python-input-1>", line 1, in <module>
range(start=2, stop=5)
~~~~~^^^^^^^^^^^^^^^^^
TypeError: range() takes no keyword arguments
However, when trying to match pattern, it only works with keyword arguments instead.
>>> match range(2, 5):
... case range(0, y, 1):
... print('1 argument')
... case range(x, y, 1):
... print('2 arguments')
... case range(x, y, z):
... print('3 arguments')
... case _:
... print('none of the above')
...
Traceback (most recent call last):
File "<python-input-0>", line 2, in <module>
case range(0, y, 1):
~~~~~^^^^^^^^^
TypeError: range() accepts 0 positional sub-patterns (3 given)
>>> match range(2, 5):
... case range(start=0, stop=y, step=1):
... print('1 argument')
... case range(start=x, stop=y, step=1):
... print('2 arguments')
... case range(start=x, stop=y, step=z):
... print('3 arguments')
... case _:
... print('none of the above')
...
2 arguments
Interestingly, those arguments can't just use any arbitrary names. Using different ones causes the pattern match to fail, without raising an exception.
>>> match range(2, 5):
... case range(aaa=0, bbb=y, ccc=1):
... print('1 argument')
... case range(aaa=x, bbb=y, ccc=1):
... print('2 arguments')
... case range(aaa=x, bbb=y, ccc=z):
... print('3 arguments')
... case _:
... print('none of the above')
...
none of the above
