Cause of the problem A variable name in a case clause is treated as a name capture pattern. It always matches and tries to make an assignment to the variable name. This is almost certainly not what was intended. Because the first matching case wins and because case OKAY always matches, the other case clauses … Read more
Change: from collections import Mapping to from collections.abc import Mapping
Example converted to pattern matching Here’s the equivalent code using match and case: match x: case int(): pass case str(): x = int(x) case float() | Decimal(): x = round(x) case _: raise TypeError(‘Unsupported type’) Explanation PEP 634 specifies that isinstance() checks are performed with class patterns. To check for an instance of str, write … Read more
You can define a default case in Python. For this you use a wild card (_). The following code demonstrates it: x = “hello” match x: case “hi”: print(x) case “hey”: print(x) case _: print(“not matched”)
Change: from collections import Mapping to from collections.abc import Mapping
You can use guards: match a: case _ if a < 42: print(‘Less’) case _ if a == 42: print(‘The answer’) case _ if a > 42: print(‘Greater’) Another option, without guards, using pure pattern matching: match [a < 42, a == 42]: case [True, False]: print(‘Less’) case [_, True]: print(‘The answer’) case [False, False]: … Read more
PEP 604 covers these topics in the specification section. The existing typing.Union and | syntax should be equivalent. int | str == typing.Union[int, str] The order of the items in the Union should not matter for equality. (int | str) == (str | int) (int | str | float) == typing.Union[str, float, int] Optional values … Read more
According to What’s New In Python 3.10, PEP 636, and the docs, you use a | between patterns: case ‘Egide’ | ‘Eric’:
If you have faced this error please refer to this answer. In order to save your time, I will post what I have done to solve the issue. Install the latest pip with the following command: curl -sS https://bootstrap.pypa.io/get-pip.py | python3.10
As Mitra said above, change: from collections import Mapping to from collections.abc import Mapping