I want to use Python's structural pattern matching to distinguish between a tuple (e.g. representing a point) and a list of tuples.
The straightforward approach does not work though:
def fn(p):
match p:
case (x, y):
print(f"single point: ({x}, {y})")
case [*points]:
print("list of points:")
for x, y in points:
print(f"({x}, {y})")
fn((1, 1))
fn([(1, 1), (2, 2)])
which outputs:
single point: (1, 1)
single point: ((1, 1), (2, 2))
whereas I want it to output:
single point: (1, 1)
list of points:
(1, 1)
(2, 2)
Switching the order of the case statements also does not help here.
What is a good way to solve this with pattern matching?
Use tuple(foo) for matching a tuple and list(foo) for matching a list
def fn(p):
match p:
case tuple(contents):
print(f"tuple: {contents}")
case list(contents):
print(f"list: {contents}")
fn((1, 1)) # tuple: (1, 1)
fn([(1, 1), (2, 2)]) # list: [(1, 1), (2, 2)]