From dbd31929d31362befd0d16b56aacad71ae831145 Mon Sep 17 00:00:00 2001 From: Micael Jarniac Date: Tue, 19 Mar 2024 18:54:32 -0300 Subject: [PATCH] Add one-of `match` example to README (#558) Removed the parts of the example that showed accessing an unset value, as it now raises an `AttributeError`, and added an example of the `match` way of accessing the attributes. Related to #510 and #358. --- README.md | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/README.md b/README.md index 4afb5a60..f7077df9 100644 --- a/README.md +++ b/README.md @@ -277,7 +277,22 @@ message Test { } ``` -You can use `betterproto.which_one_of(message, group_name)` to determine which of the fields was set. It returns a tuple of the field name and value, or a blank string and `None` if unset. +On Python 3.10 and later, you can use a `match` statement to access the provided one-of field, which supports type-checking: + +```py +test = Test() +match test: + case Test(on=value): + print(value) # value: bool + case Test(count=value): + print(value) # value: int + case Test(name=value): + print(value) # value: str + case _: + print("No value provided") +``` + +You can also use `betterproto.which_one_of(message, group_name)` to determine which of the fields was set. It returns a tuple of the field name and value, or a blank string and `None` if unset. ```py >>> test = Test() @@ -292,17 +307,11 @@ You can use `betterproto.which_one_of(message, group_name)` to determine which o >>> test.count = 57 >>> betterproto.which_one_of(test, "foo") ["count", 57] ->>> test.on -False # Default (zero) values also work. >>> test.name = "" >>> betterproto.which_one_of(test, "foo") ["name", ""] ->>> test.count -0 ->>> test.on -False ``` Again this is a little different than the official Google code generator: