If you look at the disassembly, there's no difference in python 3 (I only tested 3.7+), so it's a matter of style. There used to be a difference in python2 --

If you look at the disassembly, there's no difference in python 3 (I only tested 3.7+), so it's a matter of style. There used to be a difference in python2 -- the list option would turn into n LOAD_CONSTs and a BUILD_LIST, whereas the tuple option would just emit one LOAD_CONST. import dis def with_tuple(): for i in (1,2,3): print(i) def with_list(): for i in [1,2,3]: print(i) print("with_tuple") dis.dis(with_tuple) print("with_list") dis.dis(with_list) edit: looks like this changed in python 3.6: https://python.godbolt.org/z/rEfY9GT9W https://python.godbolt.org/z/rEfY9GT9W